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 Uhe 36ome 
 Optical Snstructor. 
 
 • ♦ • 
 
 Mow to Siecome an Sxpert 
 in Sitting Slasses. 
 
 »»»&»»»»»»»»»»»»»»»»»»» 
 
 J 
 
Uhe 3tome 
 Optical instructor. 
 
 Owing to the Laws recently passed in various 
 States, which prevent an impractical spec- 
 tacle vender from selling spectacles with- 
 out the knowledge of Optical Science, 
 and to enable them to practice at 
 home, I have compiled this Book of 
 Instructions in a short system for 
 the good of mankind, for ladies 
 and gentlemen, young and 
 middle aged people, to 
 study Optometin^ at 
 home in their 
 leisure time 
 and to en- 
 able them 
 to - 
 
 - 
 
 
 . 
 
 Practice it in all the States of the Union. 
 
 PUBLISHED BY 
 
 PROFESSOR LOUIS CONIGISKY, D. O., 
 
 Author and Proprietor, 
 DUBUQUE, IOWA. 
 
 1903 
 
 Copyrighted and Entered according: to Act of Congress, June 1, 1903, 
 in the office of the Librarian of Congress at Washington.] 
 
 FIRST EDITION 
 
THE LIBRARY OF 
 CONGRESS, 
 
 Two Copies Received 
 
 AUG 10 1903 
 
 \\ Copyright Entry 
 CUSS 0u XXcNo. 
 
 y o 7 °\ is 
 
 COPY B. 
 
 
F 
 
 PREFACE 
 
 In my experience with watchmakers and jewelers during" 
 the past 26 years probably a thousand have expressed to me a 
 desire and need for such a course of study. For these rea- 
 sons I believe that a thorough course in this branch of sci- 
 ence will meet with a hearty reception from the entire trade. 
 This is an Independent Course. It is not necessary that you 
 be a graduate in Optics in order to take this course. It is 
 intended for the watchmaker and jeweler in his daily handling 
 of spectacles as well as for the optician or oculist. It is as 
 good for the student as for the advanced optician. 
 
 The jeweler and watchmaker who has no intention of 
 taking a regular optical course will find the practical work 
 covered in this Instructor. It is worth a great many times 
 the cost in actual dollars and cents. Under the subject of 
 this book I teach the student to test and neutralize simple 
 and compound lenses ; to know a first quality lense from a 
 second or third quality; to locate quickly the axis of a cylin- 
 der ; to find the center of a lense ; to- neutralize decentered 
 lenses and prisms, and a valuable lecture on the accommo- 
 dation and anatomy of the Human Eye, and this course con- 
 sists of ninety-five questions and answers. Each lesson in- 
 cludes a lecture and quite a series of practical questions on 
 the subjects covered in the lecture. With each lecture is a 
 review and explanation and re-explaining the questions of the 
 previous lesson and setting the student right upon such 
 points as he does not fully understand. In that way every 
 subject is covered twice and the student is not permitted to 
 form wrong impressions. Each individual receives a per- 
 sonal instruction the same as if he were the only member of 
 a class. 
 
INSTRUCTOR. 
 
 This Instructor is for practicing to become a practical 
 optician and refractionist. The student will be entitled to a 
 diploma in any college if he thoroughly masters all the valu- 
 able questions and answers. 
 
 Composed by Prof. Louis Conigisky, the eminent 
 Prussian Optician and Scientist who graduated from Prussia 
 and also holds Diplomas of Honor of the most eminent Op- 
 thalmic Colleges of this country. 
 
CONTENTS 
 
 INSTRUCTION . PAGE . 
 
 1. — To Study the Power of Lenses 8 
 
 2. — To Neutralize Lenses and to find Convex or Concave Lenses. ... 9 
 
 3.— From what the Eye is Composed 11 
 
 4. — The Muscles of the Eye and Astigmatism, and to Examine 
 
 the Eyes 13 
 
 5. — The Clock Dial in Detecting Astigmatism 15 
 
 6. — To Test the Eye by Fogging, and Crosseyes 18 
 
 7. — After Fogging if you find that the Lines from 6 to 12 on the 
 
 Clock Dial, etc 20 
 
 8. — The Stenopaic Disc to find the good Meridian in Astigmatism. .22 
 
 9. — Cataract Operation and Granulated Lids 24 
 
 10.— With the Opthalmoscope we Look Into the Eye 24 
 
 11.— Accommodation and Anatomy 25 
 
 12— A Lecture on the Anatomy of the Human Eye ...27 
 
 13. — A Lecture on Physiologie 32 
 
/'Persons having normal vision will be able to read thla 
 print at e, distance of 14 inches from the eyes with ease and 
 comfort ; also will be able to read it with each eye separately. 
 Ifunabletodo so yonr eyes are defective and snould have 
 immediate attention. When the eves become tired from read- 
 ing or sewing, or if the letters look" blurred and run together, 
 it is a sure indication that glasses are needed The lenses 
 ?old in the cheap goods are of unequal density and have 
 imperfectly formed surfaces. Continued use of these poorer 
 lens-23 will result in positive injury from the constant strain 
 upon the mu^les of accommodation to supply the defects in 
 fee >i • ass.'' 
 
 INTRODUCTION 
 
 To the Students : 
 
 You will find that this course of instruction is a short, 
 concise statement of the principles which underlie and com- 
 pose the science of optics. There are several methods of 
 testing eyes. I have adopted for this course the one which 
 has proven the most accurate and altogether the most satis- 
 factory to both the patient and the operator. If you will 
 master this instruction and practice step by step you will be- 
 come an expert optician. It will require study and practice. 
 I have not used ten words to express a thought which could 
 have as well been framed in two. I have stripped the subject 
 of all superfluities and have devoted no space in proving 
 my assertion concerning refraction. Special attention has 
 been given to the measurement of the eyeball curvature of 
 the cornea and length and strength of the ocular muscles. 
 Considerable space has been given to the disease of the eye 
 and to the nervous disturbance of the whole system due to 
 the eye strain. 
 
 The way to success is clearly pointed out. You relieve 
 your fellow man by means of properly fitted glasses. Study 
 each lecture carefully and answer the questions in writing be- 
 fore taking up the succeeding study. Review each day all 
 that you have studied the day before. Make every thought 
 in these pages your own practice, each test as you proceed, 
 and you may be assured that you will become a benefactor 
 of mankind. 
 
INSTRUCTION-1 
 
 Fig. 2 
 
 It is first necessary to study the kinds and power of lenses. 
 There are only five so it will be easy to remember them. 
 We will start with the simplest form of lens which is called 
 a prism. A prism is a wedge of glass. (See figure 1.) The 
 thin edge is called the apex and the thick edge the base. 
 Rays of light passing through the prism are bent towards 
 the base. (See figure 2.) This displaces the object to an 
 eye back of the prism. Thus a person would see the object 
 much higher with one eye if a prism of 8 degrees was placed 
 base down in front of the eye producing double vision. We 
 will next consider the convex spherical lense. This lense is 
 a combination of prisms with base in center. (See figure 3.) 
 Rays of light striking the surface of this lense are brought 
 to a focus or point back of the lense, the covexity of the 
 lense determining the length of the focus. The thicker it is 
 
— 9— 
 
 in the center the quicker the lines are brought to a focus. 
 A concave spherical lense is a combination of prisms with 
 the basis out and apex or thin part in the center. (See fig- 
 ure 4.) The lines of light passing through these lenses 
 are bent towards the base, and consequently diverge and do 
 not come to a focus. A cylinder concave lense is the same 
 thickness on the axis of the glass. It bends the rays of light 
 one way. (See figure 5.) The dotted lines show the axis 
 of the cylinder. Light passing through the cylindrical lense 
 is focused to or diverged from a line ; in the spherical it is 
 focused to a pin-head point, in the cylindrical convex the 
 thick part is the axis. (See figure 6.) 
 
 These are the five lenses used in correcting all errors of 
 refraction and muscular insufficiencies. Learn these thor- 
 oughly and you will understand what lense to prescribe for 
 each defect. To illustrate : Suppose an eyeball is too short, 
 you use a spherical convex lens to get a shorter focus. If 
 the eye is too long you would use a spherical concave lens 
 to diverge the lines of light. If only one meridian of the 
 eye is at fault you use the cylindrical lense to bring forward 
 or throw back the focus in that one meridian. The optical 
 center of a lens is called the cone. (See figure 11.) To find 
 the cone hold the lens about 6 inches from a straight edge 
 card and move the lens until the edge of the card is continu- 
 ous from top to bottom, (See figure 7 and 8.) Mark the 
 the lens with ink over the line, then turn the lens half around 
 and mark the line again. Where the line crosses is the cone 
 or center. 
 
 INSTRUCTION-2. 
 
 Before studying this instruction answer questions num- 
 bered. This will form a part of your final examination. 
 
 1. What is the simplest form of a lens ? 
 
 2. What is the thin edge of a lens called ? 
 
 3. What is the thick part called ? 
 
 4. Rays of light passing through a prism are bent in 
 what direction ? 
 
 5. What is a spherical convex lens ? 
 
 6. How are rays of light bent in passing through this 
 lens ? 
 
 7. What is a spherical concave lens ? 
 
—10— 
 
 8. How are rays of light bent in passing through this 
 lens ? 
 
 9. What is a cylindrical concave lens ? 
 
 10. How does it bend the rays of light ? 
 
 The lens shown in cut 
 A. A. is out of center. To neu- 
 tralize a lens use a concave lens 
 to neutralize a convex lens and 
 vice versa. 
 
 A convex lens, if moved be- 
 fore the eye will cause objects 
 to move in the oppsite direction' 
 The rapidity of the motion will A. A. 
 
 depend on the strength of the glass. 
 
 A concave lens will cause objects to move in the same 
 direction as the hand moves. If you place a convex lens 
 over a concave lens of the same strength there will be no 
 motion and it is neutralized. In a cylindrical lense there is 
 no motion of the axis, and to neutralize the lens the axis of 
 both lenses must be parallel. When motion ceases the lens 
 is neutralized. A prism is neutralized by placing another 
 prism with base over the apex. When a card will show a 
 continuous line the prism is neutralized. (Figs. 9 and 10, in- 
 struction No. 1.) 
 
 The spherical convex lens, also called a plus lens, cor- 
 rects Hypermetropia and Presbyopia. It adds to-hplus sign. 
 The spherical concave lens is also called — lens and corrects 
 Myopia. It reduces in size ( — ) minus sign. 
 
 Cylindrical lenses correct Astigmatism. 
 
 Prisms correct muscular irregularities, often called 
 "cross-eyes" or "squint-eyes." The proper name is Stra- 
 bismus. 
 
 These are the lenses and defects of eyesight with which 
 we have to deal. Some eyes have but one defect, while 
 others have two or even more* Compounding lenses so as 
 to correct all the defects is the work that pays, both in cash 
 or favor, with the people. It is simple after you master the 
 use of the lenses. We bend the rays of light so they will 
 focus upon the retina of the eye naturally. Refraction means 
 to bend or break the rays of light. You should have a sam- 
 ple of the five lenses to examine and experiment with. We 
 will now pass on to the eye. 
 
—11— 
 
 The eye is like a photographer's camera, 
 picture upside down. We see with the brain. 
 
 Fig. 4. 
 Hypermetropia. 
 
 wmu 
 
 No. 7. 
 
 It takes the 
 
 Corrected. 
 
 This eye is too short. The focus is made by the ciliary 
 muscle which thickens the lens in the eye. 
 
 Correct with spherical convex lenses. 
 
 Myopia. 
 
 Fig. 5. No. 5. 
 
 Corrected. 
 
 This eye is too long. The focus is made in front of the 
 retina. The lines then cross and the picture is blurred. 
 Throw the focus back with a spherical concave lens. This 
 trouble makes a person near-sighted. 
 
 Astigmatism is caused by an irregular cornea the clear 
 part of the front of the eye. If the cornea is more convex 
 one way than the other the lines are bent quicker at the con- 
 vexity, and only one meridian can be focused properly. 
 
 INSTRUCTION-3 
 
 / 
 Before studying the instructions answer questions num 
 bered. This will form a part of your final examination. 
 
12— 
 
 11. What is the cone of a lens and how found? 
 
 12. How do objects appear to move when viewed 
 through a convex spherical lens which is in motion? 
 
 13. How do they appear to move when using a concave 
 spherical lens? 
 
 14. How do you neutralize a lens? 
 
 15. What is Hypermetropia? 
 
 16. What lens corrects it, and why? 
 
 17. What is Myopia? 
 
 18. What lens corrects it, and why? 
 
 19. What is Astigmatism? 
 
 20. What lens corrects it, and why? 
 
 21. When is a lens neutralized? 
 
 The eye is composed 
 of fluids and solids. Fluids 
 are: The Aqueous Humor, 
 the Crystalline Lens and 
 the Vitreous Humor or jel- 
 ly of the Eye. 
 
 Solids are : The Scle- 
 rotic, or white coat, and 
 the cornea. The middle 
 coat is the Choroid and Iris. 
 The inner coat is the Reti- 
 na, a layer of rods and 
 cones which is spreading 
 out of the optic nerve that 
 connects the brain. 
 
 Fig. 6. 
 The Internal Arrangement of the Eye. 
 
 The Crystalline Lens is back of the Iris and is sur- 
 rounded by a muscl ecalled the Ciliary muscle. The 
 lens hardens with age and the muscle is over taxed at 
 the age of 40 years, so one needs plus glasses for reading. 
 This change is called the Presbyopic change. Sometimes 
 the lens hardens and turns white. This is called Cataract. 
 Usually it can be absorbed, but sometimes it has to be re- 
 moved.. It is ripe when the person cannot count figures at 
 three feet. At the commencement of cataract the lens often 
 swells and produces "second sight." The person can read 
 without glasses because of the thickening of the lens in the 
 eye. 
 
Figure 7. THE MUSCLES OF THE EYE. 
 
 The eye is held in position and moved by six muscles 
 called the Recti Muscles. If one muscle is short and the eye is 
 turned in the case is one of manifest Convergent Strabismus. 
 Persons may have a good deal of muscle- trouble and yet 
 conceal it to the casual observer but a skillful optician readi- 
 ly discovers the error. The names of the seven muscles of 
 the eye and their functions are as follows : 
 
 Superior Recti turn the eyes up. 
 
 Inferior Recti turn the eyes down. 
 
 Internal Recti turn the eyes in. 
 
 External Recti turn the eyes out. 
 
 The Superior Oblique is attached to the top of the eye- 
 ball. It is called the "pulley muscle," as it runs through a 
 pulley then back of the equator of the eye. 
 
 These muscles are all attached at the apex of the orbit. 
 The Inferior oblique is fastened to the under part of the eye- 
 ball and back of the equator and to the bottom of the orbit 
 in front of the equator of the eye-ball. The oblique muscles 
 rotate the eye-ball when the head is moved from shoulder to 
 shoulder in order that the picture may fall in all respects on 
 the same part of the retina of each eye. The ciliary muscle 
 surrounds the lens and regulates the focus. The Iris is the 
 curtain of the eye and regulates the quantity of light admit- 
 ted. The Macula is the sensitive part of the retina, the point 
 of acute vision being straight back of the pupil. The mu- 
 cous membrane covering the eye-ball is called the Conjunc- 
 tiva and is continuous with that of the lids. 
 
— 14— 
 
 INSTRUCTlON-4, 
 
 Before studying this instruction answer questions num- 
 bered. This will form a part of your final examination: 
 
 -"' 22. Of what is the eye composed ? 
 
 23. Name the fluids ? 
 
 24. Name the solids ? 
 
 25. Name the muscles of the eye and their functions ? 
 
 26. What is the cause of Presbyopia? 
 
 27. What lens corrects Presbyopia? 
 
 28. What is Strabismus ? 
 
 29. What lens corrects Strabismus ? 
 
 30. What is Conjunctiva ? 
 
 31. What is the Macula and where situated ? 
 
 We will now pass on to a few of the terms used in the 
 optical business, which the student will be expected to com- 
 mit to memory. People like to hear you talk about Hyper- 
 metropia, Strabismus and Astigmatism. They would much 
 rather have you say their trouble is Convergent Strabismus 
 than to say they are cross-eyed. 
 
 Hypemetropia, Short eye-ball. 
 
 Myopia, Long eye-ball. 
 
 Presbyopia, Old age sight. 
 
 Astigmatism, Irregular curvature of cornea or lens. 
 
 Corneal Astigmatism, Irregular Cornea. 
 
 Lenticular Astigmatism, Irregular Lens. 
 
 Hyperopic Astigmatism, where the eye is short in one 
 meridian and normal in the other. 
 
 Myopic .Astigmatism, where the eye is long in one meri- 
 dian and normal in the other. 
 
 Mixed Astigmatism, The eye is long in one meridian 
 and short in the other. 
 
 Emmetropia, Eye in perfect focus. 
 Strabismus, Cross eyes. 
 Esophoria, Eye turns in. 
 Exophoria, Eye turns out. 
 Hyporphoria, Eye turns up. 
 Cataphoria, Eye turns down. 
 Hyperexophoria, Up and out. 
 Hyperesophoria, Up and in. 
 
— 15— 
 
 There are many other terms that one can learn. These 
 cover all the optician needs, and to make this course as easy 
 as possible and to save confusion to the beginner, we will not 
 introduce anything- that is not absolutely necessary. This 
 course will fit you to do 95 per cent of the work you need 
 and it will not pay you to handle the other 5 per cent, as the 
 conditions are diseases of the eye. 
 
 We are now ready to begin the examination of the eyes. 
 We need two cards. One has nine rows of letters of dif- 
 ferent sizes and marked from the top down as follows: 
 
 First line distance 120 feet. That is d— 120. 
 
 a person with normal vision should see 
 the line at 120 feet. Suppose your pa- 
 tient is 20 feet from the card and can on- 
 ly read that line. You will find his vis- 
 ion 20-120 or one sixth normal. 
 
 BF 
 
 Second line distance 80 feet. If at 
 20 feet he can only read the two top lines 
 you will find the vision 20-80 or one 
 fourth normal. 
 
 LCP 
 
 If he reads the third line 20-60 or d— 60. 
 
 one third or so on. 
 
 EDBT 
 
 The lines run down to ten feet, so 
 one can test in a ten-foot room if neces- 
 sary, but it is better to have the card 20 d— 50 
 feet away if possible. At 20 feet the eye 
 is at rest. As an object comes nearer we 
 begin to use our accommodation. 
 
 PNOD 
 
 D— 40. 
 
 LTCPE 
 
 INSTRUCTION-5 
 
 D— 30. 
 
 B LT EN 
 
 Before studying this lecture use the d— 20. 
 
 questions numbered. This will from a FRPOCLTIN 
 part of your final examination. 
 
 32. At what distance from the card 
 should you have a patient sit, and why? 
 
 D— 15. 
 
 NOCTEPDLBF 
 
 33. What kind of card should you D 1() - 
 
 llse ? CPOELFBINTD 
 
—16— 
 
 34. If the patient reads the 20 foot line sitting at 20 
 feet what record do you make? 
 
 35. What is Emmetropia? 
 
 36. What is Esophoria? 
 
 37. What is Exophoria? 
 
 38. What is Hyperphoria? 
 
 39. What is Cataphoria? 
 
 40. What is Hyperexophoria? 
 
 41. What is Hyperesophoria? 
 
 The other card resembles a clock dial, with heavy black 
 lines running from each hour mark to near the center. 
 
 The lines, three in each group, should all look alike. 
 
 You need a complete trial case of lenses and tests, in 
 order to fit a patient with glasses. 
 
 Test each eye separately when the patient looks at the 
 card. This can be done by placing a card in front of first 
 one eye and then the other. Never let the patient close his 
 eyes or press it with his hands or it will blur the vision. 
 
 Provide yourself with a pocket blank book and make a 
 record as follows; Vision, right eye, 20-120 (or whatever 
 your test may show;) left eye, 20-60. Pin-hole right eye, 
 20-30, left eye, 20-20. 
 
 The use of the Pin-Hole Test. If one-fourth or one-fifth 
 vision is manifest use the pin-hole disc on one eye at a time, 
 placing the solid disc before the other eye. This test is a 
 black rubber disc with a pin hole in the center, which shuts 
 off all but one ray of light which passes to the retina with 
 out refraction. If this improves the vision there is an error 
 of refraction and you can improve the sight. If this test 
 does not help, the case is almost hopeless. 
 
 After taking a record of each eye separately at 20 feet, 
 place a plus 2.50 D. lens in each side of the trial frames, 
 which you will have carefully centered before each eye. 
 This will fog an emmetropic eye so much that your patient 
 cannot read 20-120. If he reads 20-20 without glasses he 
 has no Myopia or Astigmatism. If plus 2.50 fogs him com- 
 pletely he has no manifest Hypermetropia. If he is under 
 40 years of age he has no Presbyopia. 
 
17— 
 
 The clock dial is used 
 in detecting Astigmatism. 
 If the lines from XII to VI 
 are clear, as a rule he needs 
 a minus cylindrical lens, 
 with axis at right angles or 
 at 180 degrees. If the clear 
 lines are from (III) to IX 
 he needs a plus cylindrical 
 len, axis at right angles 90 
 degrees. Do not over cor- 
 rect. Stop a little short of 
 full corrections in high de- 
 grees. First correct any 
 Myopia or Hypermetropia 
 and then correct Astigma- Fl §- 8 
 
 tism. Always try plus lenses first, then minus. 
 
 If the eyes are not alike in focus, or if the patient can 
 not see the card at 20 feet with one eye cover the good eye 
 with the solid disc and bring the test card closer until the top 
 line can be seen. Use the pin-hole test. If this improves 
 the sight an error of refraction is indicated. Work out the 
 case by fogging. Put on a plus lens strong enough to blur 
 the top line. Place lens in the back cell of trial frame and 
 neutralize the plus with minus lenses, commencing with 
 minus 50 — 75 — 100 and so on until you get the best vision. 
 The difference between minus and plus indicates the amount 
 of Hypermetropia. Example: If it takes plus 5. 00D. to fog 
 the top line and you have on minus 3.00D. to give the best 
 distant vision subtract 3. 00D. from 5. 00D, and you have 
 plus 2, 00D. remaining. If the lines on the clock dial are 
 uniform in color and size this is the correction. 
 
 Myopia, Astigmatism and Hypermetropia can all be- 
 worked out under this system of fogging. Suppose you 
 have a patient who reads 20-20 without glasses, you place in 
 the cell plus 2.50D. both eyes, and they still read 20-20, you 
 know the patient has at least 2.50D. of Hypermetropia. 
 Put plus 5.00 in the frames and if some of the cards can be 
 still read you have more than 2.50D. Reduce with minus 
 lenses until your patient can read 20-20. The difference be- 
 tween the minus and plus gives the exact amout of Hyper- 
 metropia, 
 
—18— 
 
 INSTRUCTION 
 
 Before studying this instruction answer questions num- 
 bered. This will form a part of your final examination. 
 
 42. What is the object of fogging with strong plus 
 lenses? 
 
 43. Why will a plus 2.50D. spherical lens fog one per- 
 son and not another? 
 
 44. Of what use is the pin-hole test? 
 45.- How can }^ou detect Astigmatism? 
 
 46. When the III to IX is clearest, what lens is indica- 
 ted as a rule? 
 
 47. W T hen the XII to VI is clearest, what lens is indi- 
 cated, as a rule? 
 
 Suppose you have a patient who reads 20"50 both eyes 
 and it takes plus 1.50 to fog the top line, you are almost 
 sure, provided the clock dial looks even, to have a case of 
 Myopia. Reduce the fog and stop when the patient reads 
 20-20, or when the next stronger lens fails to improve the 
 sight. The difference between the plus and the minus lenses 
 will measure the Myopia. 
 
 Do not use over 1.50 or 2.00D. difference between the 
 lenses in a pair of glasses. Fit the good eye and let the 
 poor eye go uncorrected beyond 2.00D. Example: If it 
 takes plus 1.00 on one eye and plus 4.00D on the other eye 
 to get the same vision give only plus 3.00D. on the poor eye. 
 Give the weakest minus lens that will make him see the 20 
 foot line at 20 feet. Some eyes can not be brought up to 
 perfect conditions. 
 
 After the age of 40 the Presbyopic change commences 
 and progresses to 65 or 70. This is caused by the harden- 
 ing of the Crystalline lens and shrinking of the eye-ball. It 
 will usually take plus 1.00D. lenses for reading at 45 years; 
 plus 2. 00D. at 55 and plus 3. 00D. at 65. 
 
 Always test for distant vision first, then test at 14 inches. 
 On the reading test card are letters ranging from the finest 
 to large size, after correcting the distant vision show the 
 reading card to the patient, and if he can only read to 20 it 
 indicates that a 20 inch lens or plus 2.00D. len will give him 
 perfect vision. After correcting any errors of refraction 
 hold 8 degrees of prism in front of one eye, base down and 
 have the patient look at a door knob or candle. 
 
-19— 
 
 This lens produces double vision. If one is seen direct- 
 ly over the other it shows the external and internal muscles 
 are properly balanced. Turn the base of the prism in and 
 he will see two candles horizontally. If one is not higher 
 the other the superior and inferior recti muscles balance. 
 
 A person should be able to overcome 5 or 6 degrees of 
 prism base in and 15 degrees base out. Xo test of the eye 
 is complete unless the strength of the muscles is ascertained. 
 When you place the base of the prism in your test the 
 strength of the external muscles; base out the internal. 
 
 To exercise the muscle, place the apex of the prism over 
 
 it. To rest the muscle place the base of the prism over it. 
 
 Suppose you have a patient who can overcome on a 20 
 foot test 20 degrees of prism, base in, and only 5 degrees, 
 base out. You know at once that the externals are to strong 
 for the internals in close work. Prisms are indicated base 
 in. A person should overcome from 1% to 3 degrees, base 
 up or down, as the superior and inferior recti muscles should 
 be of equal strength. 
 
 If one eye turns in set the base of the prism out. If the 
 eye turns out, set the base of the prism in. A prism which 
 brings the objects together measures the defect. The cor- 
 rection may be divided and half placed on each eye. In Hy- 
 permetropia the eye often turns in, there being a associated 
 movements between accommodation and convergence. 
 
 Accommodation is the act of thickening the lens of the 
 eye for close work. If the eye ball is short, the accommoda- 
 tion has to be used for distance. When the eye is normal, 
 the accommodation is used when the object looked at comes 
 within 20 feet, and at the same time the eyes converge, or 
 come together. If you look at the end of your nose you 
 have the appearance of being cross-eyed. 
 
 Many cases of cross-eyes in children may be cured with 
 strong plus lenses. Let the lens fog the 20 foot line if the. 
 patient will wear it. 
 
 Care should be taken in prescribing prisms. Some 
 writers claim the use of prisms criminal, but we have had 
 some excellent results where others, who were afraid, 
 failed. Use care and judgment. 
 
—20— 
 
 INSTRUCTION 7. 
 
 Before studying this instruction use the questions num- 
 bered. This will form part of your final examination. 
 
 48. After fogging the vision with plus lenses, how do 
 you proceed, and when should you stop? 
 
 4 ( ). How much difference can be made in glasses 
 where the eyes are not alike in focus? 
 
 50. Do you prescribe the weakest or strongest lens 
 with which a patient can see 20-20 in Hypermetropia? 
 
 51. In Myopia? 
 
 52. What is Presbyopia, and how corrected ? 
 
 53. How can you prove that the external and inter- 
 nal muscles balance ? 
 
 54. How much stronger should the internal muscles 
 be than the external ? 
 
 55. How many degrees of prism, base in, should a 
 person overcome? 
 
 56. How many degrees of prism base out, should a 
 person overcome? 
 
 57. Base up or down, how many degrees prism should 
 a person overcome? 
 
 58. If the eye turns in, how do you place the base of 
 the prism ? 
 
 59. If the eye turn out, how do you place the base of 
 the prism ? 
 
 In Strabismus, if the eye turns out, give full correction; 
 if it turns in, half correction. 
 
 In fitting frames care should be taken to see that the 
 nose piece is not too high or too low, too wide or too nar- 
 row. The patient must look through the center of the lens. 
 To measure the pupilliary distance, hold a rule with the 
 end in front of the center of the pupil of one eye. Where 
 the center of the other pupil comes on the rule is the measure. 
 It will run from 2 inches in children to 2 and eight-six- 
 teenths in adults, the average being 2 and six-sixteenths. 
 Occasionally we have one 2 and three quarter inches. 
 Nose glasses are not as satisfactory as spectacles. Rimless 
 
—21 — 
 
 spectacles are easily broken, and people should be warned 
 about them. A few hours practice on yourself or friends, 
 with the trial case, will fit you for active work. Place a 
 plus 3. D. in frame and your eye is made Myopic. Correct 
 this with minus sphere of same number. Place a minus 
 2. D. in frame and this makes the case Hypermetropic, and 
 that is corrected with the plus lens. It is the same with 
 the cylindrical lenses and prisms. If you will practice on 
 yourself you will understand better the cases you meet. 
 
 When the patient tells you how the chart appears you 
 will recognize the case as the same you produced in your 
 eyes with a certain lens and you will know immediately 
 what corrects that trouble. 
 
 The lenses are numbered by the Dioptric system, a me- 
 ter (40 inches), being the unit of measure. A lens of 1.00 
 D. strength focus at 40 inches or one meter. 200 D., being 
 double the strength, focuses at half the distance or 20 
 inches 0. 50 D. being half the strength focuses at 80 inches. 
 Divide 40 by the Dioptric measure of the lens and you have 
 the distance in inches at which the line focus. 4.00 D. 
 equals 10 inches, 5.00 D. equals 8 inches. 
 
 Care must be taken in writing a prescription. 
 
 1st. Let your patient wear the correction as long as 
 possible in your office to see if it is comfortable. 
 
 2nd, Be sure to use the — |— or — sign before your 
 sphere, or cylinder, and state whether prism are to be 
 base in or out. 
 
 3d. Exercise care in fitting frames to have them set as 
 close to the eyes as possible without the lashes touching 
 the glass. 
 
 4th. See that the temples are long enough and wide 
 enough to be eomfortable. 
 
 Blanks are furnished by optical companies to be used 
 in writing prescriptions. 
 
 On the two cell trial frames the outer cell revolves. It 
 is marked in degrees. If you use a plus 1.00 D. spherical 
 lens combined with a plus 50. cylindrical lens, placing the 
 axis perpendicular, you will find the pointer making 90 
 degrees. In this case you would prescribe: Right eye, plus 
 
—22— 
 
 1.00 D. spherical, combined with plus 50 D. cylindrical 
 axis 90 degrees. Left eye — what your test indicates. 
 
 After fogging with plus 2.50 spheres and gradually re- 
 ducing the fog with minus spheres, if you find that the 
 lines from VI to XII on the clock dial are very much clear- 
 er than the others, place a minus .25 D. Cylinder with axis 
 at 180. If this does not make all lines appear alike trv, 
 successively — .38, — .50, — .62, etc., until all lines appear 
 equally clear. 
 
 INSTRUCTION 8. 
 
 Before studying this instruction answer questions 
 numbered. This will form a part of your final examination. 
 
 60. Why should a person look through the center of 
 their lenses ? 
 
 61. At what distance should you test for muscle 
 trouble ? 
 
 62. How will you proceed to test eyes ? 
 
 63. Explain the Dioptric system ? 
 
 64. Name a few important points in fitting frames. 
 
 You may have this correction in your trial frame: 
 -|-plus 1.50 D. sph. 3 (combined with) — .62 cyl., axis 
 180. Suppose this gives 20-20, or perfect vision. Before 
 ordering the glasses you should transpose this into all plus 
 and let the patient try them. This is to assure yourself 
 that you have not made a mistake. To transpose a-!-, — 
 into all -|-. 
 
 Subtract the cylinder from the sphere. Bring down 
 your cylinder, but change the sign and turn the axis 90 
 degrees. 
 
 Example: -|- 1.50 Sph. — .62 cvl. axis 180 equals -|- 
 .88 Sph. -|- .62 Cyl. axis 90.° 
 
 The records you should take in each case are: 
 Distant vision (each eye). 
 Fogging with -|- 2.50 (each eye). 
 Astigmatic (each eye). 
 Pinhole if necessary (each eye). 
 
—23— 
 
 Abduction (base in) both eyes open. 
 
 Adduction (base out) both eyes open. 
 
 Sursumduction (base down or up) both eyes open. 
 
 Presbyopia (each eye). 
 
 Prescription needed. 
 
 Frame measure. 
 
 Kind wanted. 
 
 Name — age — address. 
 
 Symptoms described. 
 
 Occupation . Price charged . 
 
 Disease of eyes or lids. 
 
 The stenopaic disc is a black rubber disc with a narrow 
 opening across one way. 
 
 This is very useful in locating the good meridian in 
 cases of astigmatism and tells you the point to place the 
 axis of cylinder used. Place it in revolving cell, having the 
 other eye covered with solid disc. Move it slowly and 
 stop when vision is best and the chart looks clear to your 
 patient. Read your trial frame at the point of opening, 
 and place the axis of your cylinder at this point. 
 
 The Maddox muscle rod is an aid in locating muscle 
 trouble. It is used with both eyes open looking at alight- 
 ed candle. One eye sees the candle, the other a streak of 
 light. If one is in front of the other, the muscles balance. 
 If not, use a prism of eufficient strength to bring them 
 in line. 
 
 Spasm of ciliary muscle is caused from over-taxing the 
 eyes. It can usually be cured with strong plus lenses. It 
 is sometimes necessary to treat the eyes with antropine. 
 This treatment paralyzes the ciliary muscles, and it grad- 
 ually relaxes. It dilates the pupil of the eye. It takes sev- 
 eral days for this to wear off. This trouble usually occurs 
 in Hypemetropia. The ciliary muscle being forced to focus, 
 the distant vision is never at rest. This over work causes 
 the spasm. When testing the eyes always ask if they see 
 floating spots. Also whether they see flashes of light. 
 These arc often signs of disease of the retina. 
 
—24— 
 
 All disease arises from impure blood or nerve exhaus- 
 tion. It is useless to treat the symptoms. The true sci- 
 ence of healing is to remove the cause. Natureisthe great 
 healer. Color blindness is a congenital with about 4 per 
 cent, of men and 1 per cent, of women. It is a lack of per- 
 ception of the difference detween the seven primitive pris- 
 matic colors, viz: red, orange, yellow, green, blue, indigo 
 and violet. It is often acquired from tobacco habit or 
 other poisoning. 
 
 INSTRUCTION 9. 
 
 Before studying this instruction answer questions 
 numbered. This will form a part of your final examination. 
 
 65. Transpose -|- 3.00 D. Sph. C — 1.25 CvL 
 axis 180° 
 
 66. Transpose — 2.75 D. Sph. C -|- 2.00 CyL 
 90.° 
 
 67. Transpose -|- .50 D. Sph. O — 50 D: CyL 
 axis 180.° 
 
 68. Why should you keep a complete record of every 
 case? 
 
 69. Why is it necessary to keep a record of each eve 
 separately ? 
 
 70. Give meaning of terms Abduction, Adduction and 
 Surs-umduction. 
 
 71. Is it important to test the muscles of the eye ? 
 
 Iritis is another dangerous and painful disease. The 
 pupil contracts, eyeball becomes highly inflamed, the iris 
 has a muddy appearance. There is dread of light (photo- 
 phobia). This disease should be treated ot once by a phy- 
 sician as there is danger that the iris will become attached 
 to the lens. 
 
 INSTRUCTION 10. 
 
 Before studying this instruction answer the questions 
 numbered. This will form apart of your final exam ination. 
 
 72. What is spasm of ciliary muscles ? 
 
—25— 
 
 73. How is it cured ? 
 
 74. Of what are floating spots the sign ? 
 
 75. What is Pterygium ? 
 
 76. Name the three stages of conjunctivitis ? 
 
 77. What is color blindness ? 
 
 78. Define Glaucoma ? 
 
 79. Describe the symptoms of iritis. 
 
 In Hypermetropia the Ciliary muscle is forced to over 
 work. This causes dizziness, pain in the eyes, blurring of 
 sight while reading, nervous dyspepsia, cross eyes, and is 
 very common. 
 
 In Myopia the patient squints, has headache and holds 
 objects close to his eyes: 
 
 In Astigmatism the strain produces headache and nerv- 
 ous exhaustion. From correction people receive prompt 
 relief after doctoring for years. 
 
 I cure all these diseases by conserving the nerve forces. 
 I remove the cause, eye strain nature comes to the rescue 
 and a cure results. 
 
 With the Opthalmoscope we look into the eye and ex- 
 amine the retina. (See figure 4, Page 29). Each student 
 will derive great benefit from the use of this instrument 
 in examination, as many diseases may be detected by 
 scrutinizing of the retina. 
 
 INSTRUCTION 11, 
 
 80. What is the cause of disease ? 
 
 81 . How can it be cured ? 
 
 82. Through what nerve do we get a reflex action ? 
 
 83. What reflex is produced by strain of the ciliary 
 muscles ? 
 
 84. What are the nervous symptoms in Myopia ? 
 
 85. What nervous troubles are caused by astig- 
 matism ? 
 
 86. State the difference between an error ofrefraction 
 and an error of accommodation? 
 
—26— 
 
 £7. What parts of the eye would be touched by a line 
 passing through the optical center ? 
 
 88. What regulates the amount of light which enters 
 the eye ? 
 
 89. Why is it often possible for a hypermetropic per- 
 son to see perfectly at a distance ? 
 
 90. Do you use the Opthalmoscope? 
 
 91. Have you taken optical instructions before ? 
 
 62. About how many hours have you studied on 
 this course ? 
 
 93. Have you a trial case, and have you used it as 
 directed ? 
 
 94. Have you been helped in any way by this course? 
 
 95. Do you want to buy a trial case, or other optical 
 instruments. 
 
 8 
 
 \T< Mirn 1 1 1 1 j 1 1 , 1 1 ij n 
 
 Artificial Human Eyes* 
 
 And Hoiv to Insert Them 
 
LECTURE ON THE ANATOMY OF THE HUMAN EYE. 
 
 Our present exact knowledge of accommodation, sim- 
 ple as it now seems to us, has only been arrived at after 
 an immense amount of patience and laborious research, 
 and within the last thirty years has finally received the 
 character of an exact science. I must ask patience from 
 some of the readers, as it is impossible to explain the mat- 
 ter before us without stating some facts about anatomy 
 of the eye, and therefore I ani compelled to make use of a 
 few scientific phrases, but I hope this chapter will not be 
 overlooked on that account, for it is the very one which 
 conveys the information intended mainly to be given. 
 
 The eye is a globular body composed of three envelop- 
 ing coats holding in place the contained liquids or humors, 
 which are of a more or less resisting consistency. The eye 
 rests in a hollow bony socket, (see fig. 6, page 12) through 
 whose walls pass the optic nerve, vessels, etc., serving to 
 maintain in the normal functions of the eve. The socket is 
 lined with soft tissue, forming a yielding surface within 
 which the eye moves and which also mitigates the sever- 
 ity ol blows upon the visual organs. 
 
 The eye is moved by six muscles, (see fig. 7, page 13 \ 
 originating at the baek of the socket and passing forward 
 to their attachment upon the front of the globe, The mus- 
 cles move the eye in all directions, and a contraction or a 
 paralysis of any of them produce the deformity called 
 "cross-eye" which may usually be relieved by a suitable 
 operation upon the affected muscles. 
 
 The outer coat of the eye is called the sclerotic, and is 
 is hard, tough and unyielding, being really the skeleton of 
 the eye, maintaining it's shape and holding the other por- 
 tions in position. It is white and glistening in appearance 
 and is indicated, when reference is made to the white of the 
 eye. At the extreme front of the eye is seen a transparent 
 bulging membrane, resembling the crystal of a watch, 
 called the cornea. This is really a continuation of the scle- 
 rotic, only it is transparent, while the sclerotic is opaque. 
 It performs the same function to an eye that & window 
 does to a room, viz: it enables light to pass to the interior 
 and allows one to look out and observe what is going on. 
 If a window to a room was frosted or walled up,itsinteri- 
 
—28— 
 
 or would be dark arid one could not look out through it. 
 So it is with the eye; the cornea is the window of the eye. 
 If it becomes scarred or destroyed, light fails to pass inside 
 and sight is destroyed. It will thus be seen how impor- 
 tant it is to maintain the cornea in it's integrity, and to 
 seek competent advice in case it is even slightly diseased, as 
 a minute scar or opacity of its tissues especially if situated 
 directly over the pupil, may practically destroy fine vision. 
 The cornea is a continuation of the sclerotic of the outer 
 membrane of the optic nerve, and the latter a continuation 
 of the outer membrane of the brain; thus the eye is in re- 
 ality a portion of the brain and should be regarded with 
 the respect usually accorded to that important structure. 
 
 Passing inward the next coat of the eye is a dark, 
 bloody membrane called the choroid. It plays an impor- 
 tant part in furnishing nourishment to the eye, and 
 it passes forward to the interior portions of the eye and 
 forms a muscle called the A f 
 
 ciliary muscles or muscles 
 of accommodation which 
 envelopes the periphery, 
 of the crystalline lens, 
 (Fig. 3). As the choraid 
 passes still further for- 
 
 r . 1 FIG. 3. — (8howing the act of accom- 
 
 Ward it merges mtO What modation. The left side is in a state ofrest; 
 
 , i . the rijjht side is in the act of accommodation 
 
 IS Known as tile lriS, as can be seen by the increased thickness or 
 
 Which gives tO the peO- convexity of the lens.) 
 
 pie's eyes their characteristics color of blue, brown, black, 
 etc. The iris is a thin membrane or curtain situated just 
 back of the cornea, with a hole punched in it's middle, 
 called the pupil. 
 
 In the iris are found two muscles, which contract and 
 dilate the pupil in order to control the amount of light 
 entering the eye; thus if the eye is exposed to a bright light 
 the pupil contracts; if thelight isdimit dilates. Although 
 the pupil is merely an opening, it nevertheless looks black 
 because of the apparant lack of illumination, just as a door 
 into a closed closet looks dark because the interior is not 
 illuminated. If, however, daylight is allowed to pass 
 through any portions of the closet wall, or if we stand up- 
 on the threshold with a lighted lamp the black area of the 
 
—29- 
 
 doorway is lost, and the contents of the closet are re- 
 vealed. If light rayscan be thrown into the interior of the 
 eye and if the head of the observer does not block the way 
 to the transmission and reception of these rays the inside 
 of the eye can be accurately observed. This is done with 
 an instrument called the Opthalmoscope, which is practi- 
 cally and simply aper- 
 i orated mirror held in 
 front of the observer's 
 eje by which light is 
 reflected into the ob- 
 served eye and an im- 
 pression of it's con- 
 tents transmitted back 
 through the perforated 
 mirror to the eve of Fig 4. 
 
 the the observer. (See Fig. 4) In this way both eyes 
 are directly within the light rays, and no obstruction 
 exists to interfere with their mutual interchange. By 
 means of the Opthalmoscope the optic nerve, retina, cho- 
 roid, etc., may be clearly seen, and the wonderful picture 
 of life in veritable action accurately observed. 
 
 As the optic nerve enters the eyeball at it's posterior 
 extremity it expands into a thin membrane which lines the 
 interior of the globe and forms the delicate perception tis- 
 sue called the retina or third coat of the eye. It is a direct 
 continuation of the optic nerve and brain and into it's 
 sensitive substance are impressed the images of all we see, 
 which are then transmitted via the optic nerve to the pos- 
 terior portion of the brain, where they are interpreted at 
 sight. The eye resembles a camera and like a camera, 
 "takes pictures. " The sclerotic corresponds to the box of 
 the camera, the choroid to its black interior for the absorp- 
 tion of superfluous light, the retina to the receptive film, 
 upon which the picture of an object is impressed, the pupil 
 to the opening in front of the box, through which light 
 passes, and the lens and humors to lenses and spaces inside 
 the photographer's box. One point of difference however, 
 is noticable, viz: the film of the camera can receive only 
 one distinct impression, which it retains, but the film of 
 the eye or the retina, can receive billions of impressions, 
 
—30— 
 
 which appear and disappear with therapidity of thought, 
 as the gaze is directed at changing and ever changing 
 objects. 
 
 As we have tw r o eyes, so we see two impressions of 
 every object upon w r hich we gaze, but these two impres- 
 sions are merged or focused together, so that we appar- 
 ently see only one object, but by each eye looking at the 
 object from a some-what different aspect, the impression 
 obtained is much more general and comprehensive than if 
 observed by only one eye. Sometimes the ocular muscles 
 do not work harmoniously together in focusing the two 
 eyes upon one object, under which circumstances the intui- 
 tive muscular and nervous struggle for the proper adjust- 
 ment often produces tired eyes and headache. Unless one 
 eye gives up the struggle, and a "crossed eye" and some- 
 times double vision results. 
 
 There are three liquids of humors inside the eye — name- 
 ly, the aqueous and vitreous humors and the crystalline 
 lens in its capsule or envelopes. The Aqueous humor is sit- 
 uated just back of the cornea. It is watery in consistency 
 and is reproduced in a few hours after evacuation. The 
 vitreous humor is situated in the back of the eye, is thicker 
 in consistency and occupies about two-thirds of the ocular 
 space and is not reproduced after evacuation. The crys- 
 talline lens is swung between these two humors by a circu- 
 lar ligament attached to the inside of the eye and sets just 
 back of the pupil. It is harder than the other two humors 
 and it is surrounded at its periphery, as has been said, by 
 the ciliary muscle or the muscle of accommodation, as it is 
 sometimes called. 
 
 These muscle produces a perpetual variation in the con- 
 vexity of the lens to correspond with the size or distance 
 of an object. If a small or close object is gazed upon the 
 muscles of accommodation causes the lens to become more 
 convex and clear vision is obtained. If a larger or distinct 
 object is to be seen, the lens becomes less convex and vision 
 is again adjusted. These changes are constantly occuring 
 and the activity of this little muscle can be imagined, and 
 it will be readily understood that when inordinately used 
 under improper circumstances, it becomes fatigued and 
 
—31 
 
 characteristic eye and head pains result, which sometimes 
 require rest, improved health or glasses to correct. 
 
 The healthy lens are 
 clear and transparent, but 
 sometimes it becomes 
 milky or white, and then 
 the eye is said to have a 
 cataract, which can for- 
 tunately be cured by re- 
 moving the opaque lens 
 (fig. 5) and after replac- 
 ing it by a strong convex 
 glass lens in a spectacle 
 frame, which acts as a 
 substitute and re-establishes 
 
 FIG. 5. — (Showing the operation for 
 the removal of oataractous or opaque lens. 
 The lids are held apart by an instrument. 
 
 good 
 
 vision. 
 
 The eyelids are outwardly covered with skin, and in- 
 wardly lined with a mucous membrane called the conjunc- 
 tive, which becomes reflected into the eyeball over the white 
 sclerotic as far as the corneal margin. It is thin and trans- 
 parent and hardly visible in health, but when inflamed be- 
 comes red and swollen and more or less obscures the under 
 lying sclerotic. The conjunctive is the seat of a majority 
 of eye diseases and shows it- 
 self in the many varieties of 
 "sore eyes" granulated lids, 
 (fig. 6) etc. The body of the 
 lid between the skin and con- 
 junctive is composed princi- 
 pally of muscles which move 
 it and a little piece of tough 
 tissues which holds it in 
 shape. The lids are fringed 
 with lashes, which serve to 
 enchance the personal ap- 
 pearance and to protect the 
 eye from outside objects, 
 such as sand, cinders, etc. 
 
 FIG. 6. — (Showing the appearance 
 of "granulated lids." The upper lid is 
 turned over, showing under surface.) 
 
—32— 
 
 meant 
 
 Som times the lashes become distorted in their position 
 producing a condition 
 known as "wild hairs" 
 (Fig. 7) causing a con- 
 stant a painful scrap- 
 ing on the sensitive cor- 
 nea, which often causes 
 blindness. It can usu- 
 ally be cured by an op- 
 eration. 
 
 The tears are man- 
 ufactured in a gland 
 over the eye and pass 
 
 Onto the ball. They by ; the condition called "wild hair 
 
 are conducted towards the nose and pass into the little 
 tear-ducts at the inside of the eye in the lids, whence they 
 pass into the nose. (fig. 8) 
 Sometimes the tear-ducts be- 
 come more or less closed, 
 producing what is known 
 as " watery eyes" or con- 
 stant presence of observable 
 tears from their inabilitv to 
 pass down through the pro- 
 per channels. This condi- 
 tion can usually be cured by 
 an operation and treatment 
 upon the tear-duct, which 
 opens it up and maintains 
 its draining qualities with 
 out destroying its healthy 
 physiological action 
 
 FIG. 8. — (Showing the gland which 
 makes the tears and apparatus which 
 conveys it over the eye into the nose.) 
 
 Lecture on Physiologic and Histologic 
 
 There is a new question to consider, what has your 
 sanity to do with your eyes ? or, to put it the other way, 
 what have your eyes to do with your sanity ? The exter- 
 nal impressions upon the brain of an individual who can- 
 not see but a few inches from his nose, and in whose eyes 
 the rays of light never focus correctly, must be very differ- 
 ent from the impressions received by a normal eye, so differ- 
 
—33— 
 
 ent as to be abnormal; and though the optician may, with 
 glasses, correct to some extent the defect of the eves, he can 
 never, by mechanical means, cure the physiologic and hist- 
 ologic faults behind the eye, or restore to normal condition 
 conceivable pathologic nerve paths, and nerve centers 
 through which impression of the outer world must pass to 
 the cerebrating centers of such a brain, much less is he cap- 
 able of effacing from the brain the false impressions re- 
 ceived before glasses were worn, or still imperfect and 
 therein false and abnormal impression received since wear- 
 ing them. 
 
 An impression from without in transit would at first 
 encounter the distorting influence of defective eye, then is 
 twisted from the normal along presumably corresponding 
 defective nerve and ganglionic paths, and lastly is received 
 and metamorphosed by presumable corresponding brain 
 cells. The reflex of such cerebration is an expression of an 
 idea and the idea represents the man. 
 
 Now you can no more get strictly correct ideas, nor- 
 mal ideas from a congenitally defective head, thanyoucan 
 get pure water from a sewer. 
 
 Every person congenitally blind or partially blind i& 
 mentally abnormal. This is a startling statement, as the 
 orator of the old school would say, a statement to give us 
 pause. 
 
 Defective vision is consequently a direct cause of insan- 
 ity; prevalence of eye defects is a matter of vital interest 
 to all who have eyes, whether they see with them or not. 
 
 A person's brain is his world, each one lives in his own 
 world, and what that world is does not depend on the eye 
 it depends on the brain. One sees with the brain, Thai a 
 defect of the eye may disturb the brain and be a contribut- 
 ing cause of insanity, is to a certain degree true, because 
 insanity results from physical causes; any strain may tend 
 to produce insanity — eye strain as well as any other. 
 
 The question as to the relation existing between the 
 eye strains and diseases of the brain cannot be answered 
 without taking into consideration certain psychological 
 tacts. The brain is simply a store-house or rather a stom- 
 ach for the reception of all kinds of impressions, whether 
 
 LcfC. 
 
from the eye or other special senses, and when they are re- 
 ceived they are digested and stored away as a basis for 
 thought. If any avenue be closed or in any way limited, 
 unless it be sufficiently made up by other of the special 
 senses; certainly a weakness or perversion of mental pow- 
 er may result. 
 
 However, to say that nearsightedness or other disease 
 due to a lack of symetry of the eyeball is a proof of brain 
 degeneration, or even is a contributing cause to insanity, 
 further than the weakening or disuse of any other organ 
 which disturbs the general health and nutrition and 
 which depresses the general system is a cause, is not ac- 
 cepted. 
 
 We must remember certain fundamental facts of psyc- 
 hology. We do not see with our eyes, or hear with our 
 ears, or smell with our nose, though we do all these things 
 through them. The eye is simply a mechanical instrument 
 to the back of which a nerve is attached that conveys the 
 rays of light to the brain, or rather so irritates the nerve 
 as to produce a corresponding impression upon the brain. 
 If this same impression could bemade without themedium 
 of the eye, vision would result equally well. As a matter 
 of fact, in certain pathological conditions of the brain, we 
 do not have this phenomenon. Hallucinatians which are 
 so frequent in the insane and w^hich are not uncommon in 
 the sane are to be thus explained, in our dreams at night 
 visions are frequent, and we do not see though darkly and 
 often without vivid memory. 
 
 The child who is born blind, and later, by a cataract 
 operation with the aid of glasses is given normal vision, 
 does not see as the educated eye sees. W r e see with our 
 brain and must digest our impressions before we can judge 
 as to what we do see. This is an education in itself and 
 can only be acquired by practice. The distance between 
 our twQ eyes is simply a base line, and by this we calcu- 
 late objects. The person who has lost one eye, still has in 
 one sense good vision, — in another not, as he is at fault in 
 accurately calculating. He cannot pour his tea or hit the 
 open mouth of his ink-well. 
 
—35- 
 
 The child who cries for the noon probably thinks it no 
 farther off than is the light of a candle. A person sudden- 
 ly restored to sight is helpless until he learns to know and 
 judge of what he does see. The man who loses his arm 
 and complains that he can feel his hand and that his fin- 
 gers ache actually does feel a pain, which by mental educa- 
 tion he refers to his hand; yet it is but the irritated end of 
 a nerve which once did supply the hand even amongst so- 
 called normal individuals. Where all the special senses are 
 perfect, yet there is a vast difference as to what one re- 
 members. The artist will look at a face and at a tree or 
 a landscape, go home, vividly recall it and be able to re- 
 produce it. The effect produced by the Wagner operas on 
 different individuals bears a direct relation to brain culti- 
 vation and aptitude. The ears of listeners are probably 
 normal, but what to one is divine harmony and pleasure 
 unspeakable, is to another unmeaning jangle of inharmoni- 
 ous sounds. 
 
 It is thus seen that with perfect organs the under- 
 standing or memory is everything, and for this reason the 
 kingdom of each individual is his own brain and the limi- 
 tation is only a brain limitation. Dr. F. W. Southard, 
 who as a specialist in the diseases of the eye, enjoys a fame 
 in the capitals of Europe as well as at home, regards the 
 eye as of the higher importance in fixing and preserving 
 mental balance. 
 
 The defective eye regarded simply as an organ, will not 
 cause insanity or brain disturbance. It's the strain on the 
 brain brought about by the effort to overcome that defect 
 that does the damage. The phisiological disturbance 
 comes not from the image, but from strain. Such strain 
 is in many cases the cause of chorea, and of a nervous con- 
 dition that emulates epilepsy, and when it is very severe 
 and long continued and other condition are favorable, it 
 is possible for it to cause insanity. When the effort to see 
 — to overcomeeye defects goes beyond the normal, it causes 
 an excessive draft on the energy and drawing on the prin- 
 cipal, as it were, which is likely to exhaust the capital fast- 
 er than it can be supplied — bankruptcy break-down. 
 
—86— 
 
 Tha importance of correcting errors of vision cannot 
 be exaggerated. Through his eves the child gains his first 
 ideas of the external world, through them, aided by touch 
 and muscular sense, he learns the direction, size and dist- 
 ance of objects in space. Very early in life his mind begins 
 to take cognizance of visual impressions and upon his abil- 
 ity to correctly interpret them may depend his whole fut- 
 ure life, either for success or failure. If, through any de- 
 fect in his eyes, false or distorted pictures of objects are 
 formed upon the retina, then will his notions of external 
 world be erroneous, his judgment unreliable and but little 
 dependence can be placed upon its statements concerning 
 events coming under his personal observation. There 
 should be no cause of surprise if the child provided as he 
 is with a most marvelous organization, made to collect, 
 transmit, assort and store up in the cells of the brain the 
 products of the visual impression for future reference 
 should misinterpret their meaning, if the pictures of objects 
 looked tipon the imperfect. That the mind maybe able to 
 correct wrong visual impression it must posess a true 
 standard: such cannot in the nature of things exist; it 
 comes, and must always come, through experience. 
 
 Before the fifth year a childs perceptive powers have 
 begun to unfold. He is gradually learning the power of 
 attention. Slowly and surely his mind is being filled with 
 a desire to know, his former uncontrolled inquisitiveness 
 is gradually giving place to acquisitivenes. He asks for 
 the meaning of things. His mental horizon expands. He 
 originates ideas, he is begining to think. 
 
 During the period of receptivety the eyes should be 
 capable of seeing the most accurately. At this period of 
 life should there be errors of refraction they are most easily 
 and satisfactorily corrected. 
 
 The study of anatomy and physiology teach us not 
 only that the child may suffer physically and mentally, 
 but that his whole character may be greatly modified, or 
 even changed, by the condition of the eyes. 
 
 Perhaps at no physical point has the development of 
 man borne more heavily upon him than in the matter of 
 
—37— 
 
 his eyesight, not with-standing the wonderous power and 
 facility of that sense and the marvelous inventions in its 
 aid . The eye is the nurse and foster mother of all the other 
 senses and the patron of all the arts and sciences, and the 
 modern man is looking minutely into a myriad of things 
 and taxing his eyesight accordingly, and many are the 
 hopes that have failed and bitter has been the disappoint- 
 ment when eyesight has given way under the stress and 
 ceasless burden of the varied avocations and professions 
 of modern life, at last we are begining to realize what an 
 endless train of terrible evils attend upon the breaking 
 down and destruction of the eye under this stress and bur- 
 den, and not the least of these evils is the overstrain on the 
 already overtaxed nervous system. 
 
 That extreme, near sightedness for example, would 
 have any effect on the brain. I do not believe objects, to 
 the near sighted man, appear the same within the range 
 of his vision as they do to the man with normal eyes. 
 The only difference is that its world is more limited; what 
 he sees, he sees as well, only he does not see as far. If the 
 brain is normal his impressions are normal. Of course, if 
 his brain is abnormal, no matter how nearly perfect the 
 eye as an organ is, the impression the brain receives 
 through it are likely to be abnormal. 
 
 These impressions may be affected by the condition of 
 the eye, however, as in cases where a man is suffering from 
 alcoholism for instance, the curious things a man sees 
 when suffering from alcoholism are partly due to the brain 
 disturbance and partW due to the condition of his eyes. 
 When hesees snakes, it is not entirely dueto hallucination; 
 it is partly due to the condition of his eye. When he sees 
 as in Kipling's Lu Nuit Blanche: a blood-red mouse; it is 
 due as much to the engorged blood vessel of the eyes as to 
 a freak of imagination. 
 
*UG 10 1903 
 

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