The human eye is a remarkable, complex organ that adjusts to different lighting conditions and focuses the rays of light that enter the eye. It is protected by a bony cavity and by the fat in which is embedded, and which acts as cushioning. Also, the eye is protected from particles that may injury it by the eyelashes and eyebrows. The eye is approximately 1 inch wide, 1 inch deep and 0.9 inches tall and is comprised by different parts, each playing a vital role in providing clear vision.