Question

What are hypermetropia and myopia? What are their causes? How are they rectified?

Answer 1

Answer:

Myopia=When light rays converge in front of the retina.

Rectification=Concave lenses are used.

Myopia occurs when the eyeball is too long.

Hypermetropia=When light rays converge behind the retina.

Rectification=Convex lenses are used.

Abnormal shape of the cornea causes this.

Answer 2

A person with hypermetropia or long sight can see clearlyobject far away from them , butnot close to them. this is caused by the shape of eye- the eyeball is slightly too short.

Myopia- A short sightdness,occurs when the eyeball is too long so it affects how the cornea and lens focus.This means the object in the distance appear blurry because light rays are focusing at the front of retina rather than directly on its surface.