Question

A human eye is a convex lens. In normal eyesight, the image of an object in front of our eyes is formed exactly on the retina and is inverted. In farsighted and nearsighted eyesight, where is the image formed? Which lens can be use as a corrective measure in each case? You may use online or other resources to help you answer this question. Be sure to record your research sources in the References section near the end of this document.

Answer 1

In farsighted eyesight (Hypermetropia )

A person  with  hypermetropia  can  see  distant  objects  clearly but cannot see nearby objects distinctly.The light rays from a close by object are focused at a point behind  the retina  

In nearsighted eyesight (Myopia )

A person with myopia can see nearby objects clearly but cannot see distant objects distinctly.the image of a distant object is formed  in  front  of  the  retina

corrective measure in each case

1. In farsighted eyesight

This defect can be corrected by using a convex lens of appropriate power

2. In nearsighted eyesight

A  concave  lens  of suitable power will bring the image back on to the retina and thus the defect is corrected.