Question

Explain clearly why, a person who has lost the sight of one eye is at a disadvantage compared with the normal person who has two good eyes. 

Answer 1

A person who has lost sight in one eye is at a disadvantage for the following reasons.
(i) The person's field of view decreases. Having two eyes enables a person to see a larger area around him or her. With only one eye, the field of view becomes limited to only about 150^o.
(ii) The person's ability to accurately judge the distances of objects decreases. In the case of a person with two good eyes, both the eyes would focus on the same object at different angles and send two images to the brain that slightly differ from each other. The brain then combines the two images to form a three-dimensional image of the object, which helps the person to judge the distance of the object accurately. With one eye, it becomes difficult to judge the distance accurately.