Tag: physics

The iris is the area of the eye that contains the pigment which gives the eye its colour.

In eye light passes through the eye's lens and falls on the retina. The mechanism is same as a convex lens converges parallel beams of light in its focus.

When the light is very bright, then iris makes the pupil contract so that less amount of light enters into the eye.

The ciliary muscle is found in the middle layer of eye.  It is responsible for viewing objects at various distances. It helps to change the shape of the lens within the eye and holds it in position.

Image on the retina remains for 1/20 sec.

Middle vascular coat that darkens the eye chamber and prevents refraction by absorbing the light rays is choroid.

Eye lens is a transparent double-convex lens. Its focal length is adjustable in a manner such that a real image is formed on the retina.

Eye lens contains a watery liquid called the aqueous humour. Its major functions are immunity, nutrition, maintaining spherical shape and maintaining the required refractive index.

Iris controls the amount of the light entering the eyes through the pupil by opening or closing. The iris is the ring of pigmented tissue surrounding the pupil that varies in color.

The eye consists of a screen called retina which generates the sensation of sight. When light rays are focussed on it, an image is formed on the retina. The retina consists of light sensing cells which send signals to the brain, whenever such images are formed.