Vision and the Human Eye

Shape. Colour. Depth. Brightness. Distance. Which single organ in the human body allows one to perceive these entities? The human eye. The eye is the most important organ in discovering the world around us. Although the eye measures only 2.5 centimeters in diameter, it can see as far away as a star and as tiny as a grain of sand. It can quickly adjust its focus between distant and near points, even while the head is moving. We use our eyes in everything we do- from reading and working to watching movies and playing games. Therefore, sight is a very precious, and fragile, sense. Though many do not ponder it, the ability to see and see clearly is quite a phenomenon. Here is an explanation of the structure of the human eye, how the eye sees, and some deficiencies that impair proper vision.

THE HUMAN EYE:
When compared to the eye of various other species that can only differentiate between light and dark, the human eye is a fairly complex organ. Capable of distinguish...