Question

Answer the following.

State the function of iris and ciliary muscles in human eye.

Answer 1

The iris is a thin, circular structure in the eye, responsible for controlling the diameter and size of the pupil and thus the amount of light reaching the retina. The color of the iris gives the eye its color. In optical terms, the pupil is the eye's aperture and the iris is the diaphragm that serves as the aperture stop.

The ciliary muscle is located in the eye and surrounds the lens. It contracts or relaxes in order for an individual to see at multiple distances. When it contracts, it pulls forward, moving to a frontal portion to relax the fibers that hold the lens in place; this process also allows it to take on a more spherical shape to provide short range focus.