TERMINOLOGY
How the eye functions
The eye functions on much the same principle as a camera. The iris, or colored portion of the eye, acts as the shutter to regulate the amount of light admitted into the eye. The cornea (the clear window at the front of the eye) and the lens, located behind the pupil, serve to focus the light rays from the object viewed onto the retina in the back of the eye. The retina then transmits the "picture" of the object viewed to the brain where the object is then "seen." Myopia
Myopia is a condition in which light rays entering the eye are focused in front of the retina instead of directly on it, as in a normal eye. It has the same effect as taking a picture with a camera out of focus. Myopia is an inherited condition . It usually starts in childhood and stabilizes in the late teens or early twenties. Patients with myopia see near objects more clearly, and far objects appear blurry or even indistinguishable. Hyperopia
Hyperopia is a condition in which light rays entering the eye are focused behind the retina instead of directly on it, as in a normal eye. It is an inherited condition. It is present in childhood but does not usually become apparent to most people until they are in their late thirties, when they can no longer use their own muscles inside the eye to overcome it. Patients with hyperopia begin to have difficulty seeing things clearly in the distance or at near unless they wear glasses or some other type of optical correction. As we grow older, we all start to have difficulty reading and may require reading glasses or a bifocal. This is a condition known as Presbyopia. Presbyopia (Mid-Life Reading Problem)
presbyopia is a condition that becomes apparent around age 40 in all human beings. It comes from the lens inside the eye losing its ability to change shape to focus on near objects. In normal sighted eyes, presbyopia manifests itself as difficulty reading, requiring a pair of reading glasses. In hyperopic or far-sighted eyes, it manifests itself as difficulty in reading in addition to problems in seeing in the distance, requiring a bifocal. In the myopic eye, it manifests itself as difficulty in reading and the need for bifocal or in some instances removal of corrective lens to read. Astigmatism
Astigmatism is the eye condition in which the curve of the cornea is uneven (it is not entirely spherical in shape). This irregularity makes it difficult for the patient to focus.
© 2008 Maddox Laser Eye Center | Privacy Statement
No materials herein may be reproduced in any manner without written permission of Maddox Laser Eye Center