Sclera (white part) of the human eye

Photomacrograph of a close-up view of part of a human eye. The sclera is the white part of the eye, which forms a tough, outer coating to protect the eyeball. Part of the iris (brown) and some eyelashes are also visible here. The human eye is a complex organ and works in a similar way to a camera. Light enters the eye through the pupil. The size of the pupil is controlled by the iris in order to adjust how much light enters the eye at any given time. Light enters the eye and is focused onto the retina at the back of the eye, which then converts these images into electrical signals and sends them on to the brain to interpret and make sense of. Width of image is 2 cm.