The Eye - a miracle

Rays of light entering the eye are bent, or refracted, by the cornea and lens to produce a sharp ime on the retina. From the retina the light rays are transformed into electric pulses which are transmitted to the brain, via the optic nerves, for processing.

Similar to changing a camera's aperture, the pupil regulates the amount of light entering the eye by altering its width. This is controlled by the muscles in the iris.

The point at which the light rays are compiled is known as the Macula. This is a very small area of the entire retina (2%), but it is essential for our ability to read. The other 98% of the retina makes up our so called "field of vision" enabling us to recognize movement and objects in our middle and peripheral vision.

Ideally both close and distant imes are sharply focused on the retina without aid. The eye must change its focal length for close imes. This is known as accommodation. For close objects the lens bends increasingly to refract the light more strongly. For distant objects the lens flattens itself. In both cases the light is refracted to ensure exact light compilation on the retina.

A sharp reproduction on the retina is a necessity for good vision. In order for a truly sharp ime to be reproduced many conditions must be met. For example the length of the eye must be in exactly the right proportion to its refraction power. Only then can sharp imes be seen. This is the usual scenario for normal sighted people.

However vision impairments often occur which mostly need correction.