Question

When we enter in a dark room from a bright area, our vision is impaired for few seconds. Why does this happen?

• A. We cannot see in dark room
• B. Our eye shifts the retina more closer to our eye lens to form the image correctly
• C. Pupil takes time to adjust
• D. Rods and cones are ineffective in dark

Answer 1

The correct option is C

Pupil takes time to adjust

When we are in bright light the pupil contracts to allow adequate amount of light sufficient for visibility but as we enter a dark room the amount of light passing through the pupil is not sufficient to assist visibility. Hence, our pupil expands. This adjustment takes a few seconds till which our visibility is impaired.