Question

differentiate between myopia and hypermetropia on the basis of their change in the focal length of the eye lens and size of the eyeball

Answer 1

myopia is short sightedness and hypermetropia is long sighted ness

Answer 2

In myopia the image of distance object forms in front of the retina

The curvature of the cornea and the eye lens increases .The muscles near the lens cannot relax so that the converging power of the lens remains large

The eyeball elongates so that the distance between the length and the retina increases

In hypermetropia the images of nearby objects get formed behind the retina

Curvature of the cornea and the eye lens decreases so that the converging power of the lens become less

Due to the flattening of the eyeball the distance between the lens and retina decreases