VISION. 575 
within the vitreous humor, and diffusion-circles being formed 
on the retina, the image of the object is necessarily blurred, 
Fie. 416.--Diagrams to illustrate conditions of refraction in normal eye when unaccommo- 
dated (passive, or negatively 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 
Fig. 417.—Anomalies of refraction in a myopic eye (after Landois). 
point is abnormally near and the far point also, for parallel 
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- 
over, there is also generally, in bad cases, “spasm of accommo- 
dation” (i. e., of the ciliary muscle), with increased ocular 
tension, etc. The remedies are, rest of the accommodation 
mechanism and the use of concave glasses. 
3. The opposite defect is hypermetropia. The hypermetropic 
