LIVING LENS 



88 



pathological states of the underlymg cortex this " shagreen " 

 lustre acquires iridescent-like colourings. ]More intense and more 

 obstructive zone-like changes are shown in the deep cortex, both 

 anterior and posterior, in Fig. 50, C. What in this picture might 

 appear to be an extension into the vitreous is in reality only that 

 portion of the zone-like 

 change which is faintly illu- 

 minated by lateral scatter 

 of light in it beyond the 

 confines of the optical 

 section and is viewed by 

 retroillumination against 

 the posterior end of the 

 section. 



The slit-lamp makes it 

 possible to study, in their 

 early state, minute changes 

 in the lens more easily 

 than heretofore. Any in- 

 dividual, from the age of 

 about forty-five, is apt to 

 show minute lens-changes, 

 forerunners perhaps of 

 truly senile processes not 

 due for yet another two or 

 three decades and of little 

 more significance from the 

 point of view of " decay " 

 than is the occurrence of a 

 few grey hairs on the head. 



Fig. 50. — A, Slit-beam showing a plaque- 

 like change in the anterior lens-cortex. 

 B, The same viewed as an opacity by 

 the ophthalmoscope. C, Pathological 

 changes in the anterior and posterior 

 lens-cortex. 



(Drawing by Theodore Hamblin, Ltd.) 



But all too often the patient 

 is told of these small changes, or what is more likely he, or circum- 

 stance, forces an admission as to their presence ; from this it is but 

 a short step in the patient's mind to the significance of the term 

 " cataract." Up to the present time there is no scientifically 

 proved specific means of arresting these minute physiologically 

 retrogressive changes — when they are purely senescent and are not 



