How does lens focus light on retina

View Video. The iris works like a shutter in a camera. It has the ability to enlarge and shrink, depending on how much light is entering the eye. This clear, flexible structure works like the lens in a camera, shortening and lengthening its width in order to focus light rays properly.

Light rays pass through a dense, transparent gel-like substance, called the vitreous that fills the globe of the eyeball and helps the eye hold its spherical shape.

In a normal eye, the light rays come to a sharp focusing point on the retina. The retina functions much like the film in a camera. It is responsible for capturing all of the light rays, processing them into light impulses through millions of tiny nerve endings, then sending these light impulses through over a million nerve fibers to the optic nerve.

Because the keratoconus cornea is irregular and cone shaped, light rays enter the eye at different angles, and do not focus on one point the retina, but on many different points causing a blurred, distorted image.

In summary, the cornea is the clear, transparent front covering which admits light and begins the refractive process. A A A Type size. Commercial Moorfields Private Moorfields Dubai. Other Sites Biomedical Research Centre. Site Settings Cookie settings. Jump to content. The five senses include sight, sound, taste, hearing and touch. Sight, like the other senses is closely related to other parts of our anatomy. The eye is connected to the brain and dependent upon the brain to interpret what we see.

How we see depends upon the transfer of light. Light passes through the front of the eye cornea to the lens. The cornea and the lens help to focus the light rays onto the back of the eye retina. The cells in the retina absorb and convert the light to electrochemical impulses which are transferred along the optic nerve and then to the brain.

The eye works much the same as a camera. The shutter of a camera can close or open depending upon the amount of light needed to expose the film in the back of the camera. The eye, like the camera shutter, operates in the same way. The iris and the pupil control how much light to let into the back of the eye. When it is very dark, our pupils are very large, letting in more light. The lens of a camera is able to focus on objects far away and up close with the help of mirrors and other mechanical devices.

The lens of the eye helps us to focus but sometimes needs some additional help in order to focus clearly.