Question: explain how does light happen to affect a persons eye sight

Cheryl Andisi answered on 25 Jan 2017:

@sumseno,
Your eyes are the organs designed to collect light information and send that to the brain for interpretation thus enabling you to see. What you see is as a result of how much light that object can absorb or reflect. To do this, the eye is designed in a very special way. First, it has a lens, which focuses images on your retina at the back of the eye. Your retina has cells called rods and cons and these cells contain special proteins that will react differently to different lights, and convert that information to an electric current which is then sent to the brain for interpretation. Eyes have circular muscles surrounding the lens, whose main function is to adjust the diameter of the pupil allowing the eye to control how much light enters in the same way an aperture in a camera would. If the light intensity is too high, the muscles will reduce the diameter and during low light eg at night increase the diameter of the pupil. The circular shape of the eye is maintained due to very high pressure within the eye. This circular shape is an adaptation that allows for focusing of Images