Question

Explain the mechanism which helps to (a) see in dim light as well as in bright light (b) see nearby and far away objects (Class 10 )

Answer 1

a) When one has to see in dim light the pupil expands, allowing more amount of light to enter in the eye.

Whereas, when one has to see in bright light our pupil contracts, allowing a low amount of light to enter the eye.

b) When we have to focus on nearby objects, our ciliary muscles contract causing our eye lens to thicken and focal length to decrease, thus allowing us to see nearby objects.

Whereas when we have to focus on distant objects, our ciliary muscles relax, causing eye lens to a thinner and focal length to increase thus allowing us to see a distant object distinctly.

I hope that helps!!