The human eye is an organ that reacts with light and allows light perception, color vision and depth perception. The eye is made up of a number of parts, including the iris, pupil, cornea, and retina. The eye has six muscles which control the eye movement, all providing different tension and torque. The eye works a lot like a camera, the pupil.
The availability of light, the source of light, the direction from which the light is falling on the human eye, the physical condition of the individual; blood pressure, sugar and diabetes level, mental health, psychological health, and age are some of the factors influencing human vision. The amount of light falling into the lens and retina is.