Is a hole in the middle of the iris where light is allowed to continue its passage. In bright light it is constricted and in dim light it is dilated

Is a pigmented muscular structure consisting of an inner ring of circular muscle and an outer layer of radial muscle. Its function is to help control the amount of light entering the eye so that:

- too much light does not enter the eye which would damage the retina

- enough light enters to allow a person to see

Is a transparent, flexible, curved structure. Its function is to focus incoming light rays onto the retina using its refractive properties

Is a layer of sensory neurones, the key structures being photoreceptors (rod and cone cells) which respond to light. Contains relay neurones and sensory neurones that pass impulses along the optic nerve to the part of the brain that controls vision

A light - sensitive layer of tissues at the back of the eye that turns light into electrical signals

What is the correct order of photoreception?