Refractive Problems

These problems are caused by change in the shape and positioning of certain parts of the eye. Myopia is one of these. It is also called short-sightedness. If you have this problem, objects close at hand can be seen clearly. Objects in the distance appear blurred.

The following are common vision defects can be rectified using glasses. They are all caused by the shape and positioning of certain parts of the eye.

Myopia

HT Image

This is also called short-sightedness. If you have this problem, objects close at hand can be seen clearly. Objects in the distance appear blurred. This can be caused by:

An eyeball that is too long

A cornea that has too much curvature

The image falls before, rather than on, the retina. This is corrected by using diverging (concave) lenses.

Hypermetropia

This is called long-sightedness. In case you have this complaint you will be able to see things far away clearly and the objects close by will appear blurred.

This can be caused by:

An eyeball that is too short

A cornea that has too little curvature

Here the image falls behind the retina. Converging lenses are used to correct this defect.

(To be continued)

(Source: Webhealthcentre.com)