1. It is the defect in which a human eye can see nearby
objects clearly but is unable to see distant objects clearly.
2. In myopia, the image of distant object is formed in
front of retina.
3. There are two possible reasons of myopia :
a. As ciliary muscles do not relax sufficiently,
converging power of eye lens becomes high.
b. The distance between eye lens and retina increases as
the eyeball is lengthened or lens is curved.
4. A concave lens of suitable focal length can correct
this defect.
5. The power of concave lens is so chosen that it creates
required divergence and hence after the converging action of eye lens, the
image is formed on the retina.
