VISION. 



637 



resented as more bulging, from accommodation, as such diver- 

 gent rays are properly focused. 



3. In the myopic (near-sighted) eye the parallel rays cross 

 within the vitreous humor, and diffusion-circles being formed 

 on the retina, the image of the object is necessarily blurred, 



E-6 



Fig. 384.— Diagrams to illustrate conditions of refraction in normal eye when nnac- 

 commodated (passive, or nearly accommodated), and when accommodated for 

 " near " objects (after Landois). 



SO that an object must, in the case of such an eye, be brought 

 unusually near, in order to be seen distinctly — i. e., the near 

 paint is abnormally near and the far point also, for parallel 



-/•'^i 



Pig. 385.— Anomalies of refraction in a myopic eye (after Landois). 



rays can not be focused ; so that objects must be near enough 

 for the rays from them that enter the eye to be divergent. 



The myopic eye is usually a long eye, and, though the 

 mechanism of accommodation may be normal, it is not so 

 usually, the ciliary muscle being frequently defective in some 

 of its fibers, which may be either hypertrophied or atrophied, or 

 with some affected one way and others in the opposite. More- 



