Question

What is myopia (or short sightedness)? What is the cause of this defect? How can this defect be minimized? Explain drawing a ray diagram.

Answer 1

Myopia or short-sightedness : Myopia is a defect in the vision, in which a person can see nearby objects clearly but cannot see the distant objects distinctly after a certain limit. This defect is common among children.

The causes of Myopia are :

i) The eyeball gets elongated along its axis so that the distance between eye lens and retina becomes larger.

ii) Due to excessive curvature of cornea, The focal length of eye lens becomes small.

This defect is minimized by the concave lens of focal length equal to distance of far point from the eye.