Question

If you walk from a dark room into sunlight and back again into dark room, how would your pupils alter

in size ? What makes this happen ?​

Answer 1

When you walk from a dark room into sunlight, your pupils will naturally respond by constricting, which means they become smaller in size. This is known as pupillary constriction or miosis.

The main reason behind this pupillary response is to regulate the amount of light entering the eyes and protect them from potentially harmful levels of brightness. When exposed to bright light, the muscles in the iris contract, narrowing the opening of the pupil. This reduces the amount of light that reaches the sensitive retina at the back of the eye.

Conversely, when you walk from a brightly lit area back into a dark room, your pupils will dilate, or become larger in size. This dilation, known as mydriasis, occurs in order to maximize the amount of available light entering the eyes. By widening the pupils, more light can pass through and reach the retina, allowing for better vision in low-light conditions.

These adjustments in pupil size are automatic and regulated by the autonomic nervous system, specifically the muscles of the iris. The iris responds to the surrounding light level and adjusts the size of the pupil accordingly.

Answer 2

When you move from a dark room to sunlight, your pupils get smaller to protect your eyes from the brightness. When you go back to a dark room, they get larger to help you see better in low light. This is a natural response controlled by your eye muscles.