4. Explain the terms ‘adaptation’ and ‘accommodation’ with reference to the eye.

Solution:-

Adaptation:

For a brief period of time, when you move from a highly lit area to a dark environment (such as a movie theatre), you have difficulties seeing items. Your vision gradually improves. Dark adaptation is the term for this improvement. This is due to the rebuilding of the visual purple or rhodopsin, the rod pigment, which had previously been broken down by strong light. When a person with dark-adapted eyes walks to a brilliantly lit place, such as leaving a movie theatre after the noon showing, he gets a brief dazzling impact. After a short period of time. Through light adaptation, he returns to normal viewing.

Accommodation:

The image of an object should be in sharp focus in each eye to view it clearly. The power of accommodation of the eye is the process of focussing the eye to view objects at varied distances. This is mostly caused by a change in the curvature of the elastic lens, which causes it to become thinner or thicker. The lens is more flattened or narrower for distant vision. The lens becomes more convex or rounded for near vision.