The human eye is one of nature's most complex wonders. We depend on our eyes more than any other sense, however many of us take this precious gift for granted. Without them, we could not experience a beautiful sunset, see the faces of our loved ones, or view the natural marvels of the world. We rely on our eyesight for so much, but most people have only a vague idea of how our eyes work. There are actually many different parts of the eye working together to form a unique self-sustaining system. Though smaller than a ping-pong ball, the eye allows us to see, while cleaning, moisturizing and disinfecting itself at the same time.

The eye allows us to see and interpret the shapes, colors, and dimensions of objects in the world by processing the light they reflect or emit. The eye is able to detect bright light or dim light, but it cannot sense objects when light is absent.

The average newborn’s eyeball is about 18 millimeters in diameter, from front to back (axial length). In an infant, the eye grows slightly to a length of approximately 19½ millimeters.
The eye continues to grow, gradually, to a length of about 24-25 millimeters, or about 1 inch, in adulthood. A ping-pong ball is about 1½ inch in diameter, which makes the average adult eyeball about 2/3 the size of a ping-pong ball.

The accessory organs of the eye include:

Eyebrows, eyelids, and eyelashes

The lacrimal apparatus

Bones and muscles of the orbitals

The structure of the eye:

The Outermost Layer - the Fibrous Tunic

The Middle Layer - the Vascular Tunic

The Innermost Layer - the Retina

The Optical Structures

6 Tips for Eye Health and Maintenance