2.86 Eye as a receptor

2.86 describe the structure and function of the eye as a receptor

Information is collected by receptor cells, which are usually grouped together in sense organs, also know as receptors.

Each type of receptor is sensitive to a different find of change or stimulus.

The eye is a receptor that detects light.

The iris (right shaped, coloured part of the eye) controls the amount of light entering the eye by controlling the size of the hole in the centre, the pupil. The iris contains circular and radial muscles. In bright light the circular muscles contract and the radial muscles relax, making the pupil smaller. This reverses the amount of light entering the eye, as too much could to damage. The reverse happens in delight, when the eye has to collect as much light as possible to see clearly.

The thick clear cornea bends light rays as they enter the eye in order to bring them to a focus on the retina. The lens provides fine focus to sharpen the image.