Question

Why do humans have two eyes?
a. The view field is increased up to ${180^ \circ }$
b. Better detection of faint objects
c. $3$ dimensional view
d. More accurate estimation of distance

A) a, b and d
B) c and d
C) a, c and d
D) All of the above

Answer 1

Human beings have two eyes and a vision with two eyes is called binocular vision. Since our eyes have distance between them, so each eye sees a different image.

Complete step-by-step answer:
Step I:
With two eyes, human beings can see objects with a much wider field of view. A field of view is the extent or maximum distance up to which the objects can be seen at one moment. In human beings, with one eye the field of view is${150^ \circ }$ which is increased to${180^ \circ }$ with two eyes.
Step II:
It also enhances the ability to detect faint objects. Faint objects are the objects that are not clearly visible to our eyes. With one eye, humans can not see faint objects much clearly, but with two eyes this ability is improved.
Step III:
It enables humans to view objects in three dimensions. It enhances and enables the eyes to see objects with great depth of perception.
Step IV:
Since there is distance between eyes so the brain receives different images from both the eyes. It monitors slight differences in both the images and then calculates the distance between the objects. The image is then formed on the retina.

Option D ‘All of the above’ is the right answer.

Note: Depth of perception is the ability of the human eyes to see objects in three dimensional view. Although the objects can be seen with one eye also, but with one eye or with binocular vision, the depth of perception is poor. But in binocular vision the depth of perception increases.