Understanding the Eye

Eye - Toronto Eye Clinic

The eye works much like a camera. When you take a picture with a camera, outside light enters the camera, travels through the lens in the front, and is then focused by the lens to form an image on the film on the back inside wall. The front parts of the eye (cornea, pupil, lens) are clear and allow light to enter. The cornea and lens focus incoming light on the back inside wall (retina) of the eye. So the retina, a thin layer of tissue covering the back inside wall of the eye, is like the film in a camera.

It's interesting, however, that the eye cannot see this "picture". The brain itself supplies our vision and so the image made on the retina must be transported to the brain. This transportation is done by a structure called the optic nerve. The optic nerve connects the eye and brain. The brain is where the image is developed into a picture . . . and thus we see!

Understanding the Retina

Retina Toronto Eye Clinic

The central retina, or macula, allows us to see fine detail such as reading fine print, threading a needle or recognizing a face. This is the most sensitive part of the retina. The macula must be healthy for it to work properly. The peripheral retina gives us the ability to see "side" vision or "peripheral" vision. Because the peripheral retina is not sensitive enough to see detail, we cannot read fine print, thread a needle, or recognize a face using peripheral vision.

Since the macula must be healthy for it to work properly, it is important that everyone has an eye exam periodically so that any changes or problems can be detected early. By detecting a problem with eyesight early, the chance of saving vision is much greater. Once damage to the macula has occurred, the success of treatment is much less.