102 KANSAS Academy of Science. 



being progressive, it becomes necessary to use a stronger glass every few years. 

 Presbyopia may occur before the age of forty, but is to be distinguished from Hy- 

 permetropia, or far-sightedness, a condition due to a shortening of the globe of the 

 eye itself, which may be congenital, or develop at an early age. The two are often 

 confounded, owing to the fact that a convex glass is worn in either case; but hyper- 

 metropia is far more difficult of correction, owing to the fact that it is rarely de- 

 tected in its incipiency, and in the effort to bring rays of light from near objects to 

 a focus on the retina the patient strains the accommodation, producing a condition 

 of spasm, sometimes associated with squinting, and this spasm is very difficult to 

 relax. Jewelers and trade dealers in spectacles frequently fail to give satisfaction 

 in fitting glasses, because they do not understand the pathology of spasm, and a 

 glass which suited the patient in the store may prove very unsatisfactory when worn 

 constantly for an hour or two at home. 



Cataract, so called from its causing a blindness like that of a veil falling over the 

 eye, is a cloudy or opaque condition of the crystalline lens, which prevents the pas- 

 sage of rays of light to the retina. The causes are still obscure; but it occurs more 

 often with certain diseases such as diabetes and ergotism, after injuries to the eye, 

 in persons of dissipated habits, and often with no other apparent cause than the 

 lowering of vitality due to advancing years. The ordinary senile cataract is of slow 

 formation, from two to four years intervening between the first symptoms and that 

 condition of hardness in which it is said to be ripe. The opacity may begin in the 

 center, at the periphery, or at the poles. When it begins in the center or at the 

 poles there is better vision on dark or dull days, or when the eye is shaded, for then 

 the pupil dilates, and rays pass through the as yet unclouded periphery of the lens. 

 The symptoms of cataract are: Failing vision, unimproved by glasses, and more 

 marked in one eye than in the other. Later, the pupil, which formerly was black, 

 shows a cloudy gray or purplish appearance; and examination by oblique illumina- 

 tion and the use of the ophthalmoscope shows the seat and extent of this cloudiness. 

 During the earlier stages of cataract, the fundus of the eye can be seen with the 

 ophthalmoscope, and it is very important that a careful examination should be made 

 at this time, to determine the advisability of an operation when the whole lens be- 

 comes opaque. No treatment is of any avail, except removal of the lens when it is 

 ripe, or, in selected cases, the making of an artificial pupil by removing a small 

 portion of the iris from in front of a clear portion of the lens. Even when a cata- 

 ract is ripe the patient is not absolutely blind, for, when placed facing a window, he 

 will detect a hand passed between him and the light, and in a dark room he is able 

 to tell the position of a lighted candle placed before him or at one side. When this 

 perception of light is lost, there is some other defect, and operation is not advisable; 

 but in all ordinary cases, after the cataract is removed, very good vision is secured 

 by placing strong convex lenses in front of the eye. It must be remembered, how- 

 ever, that the accommodation is lost, and lenses of different foci are required for 

 seeing at varying distances. 



Several of the leading oculists have made themselves famous by devising new 

 operations for cataract. Formerly the lens was dislodged from its position by nee- 

 dles, and pressed back into the vitreous humor; but now the favorite operation is to 

 remove the lens bodily by an incision through the cornea, and the principal differ- 

 ence of opinion is as to the advisability of removing a portion of the iris first, or 

 pressing out the lens, and running the risk of bruising the iris during the operation. 



Dr. Valk, with whom I spent some time during a recent period of study in New 

 York, has devised an operation by which he presses back the iris with retractors 

 during the exit of the lens, thus avoiding the dangers of inflammation of the iris, 

 and securing a perfectly round and movable pupil after the operation. 



