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Tulane Doctors- Refractive Center - Refraction 101

The eye is remarkably complex. However, we’ll attempt to keep things simple here by providing some very basic information about refraction and its impact on vision.

Refraction simply means the bending of light rays. The way in which the eye bends light rays affects how we see. With perfect vision, the light rays enter the eye, are bent in such a way they join or converge perfectly on the retina (back of the eye). But various abnormalities and changes in the eye over time can alter the way light rays are bent, bringing about changes in the way we see.

Basic Errors of Refraction

Normal Eye
normal eye illustration With perfect vision, the light rays enter the eye, are bent in such a way they join or converge perfectly on the retina (back of the eye).
Myopia (Nearsightedness)
myopia eye illustration Myopia (nearsightedness) occurs when imperfections of the eye cause light rays to bend and converge at a point in front of the retina. This causes blurred vision when viewing distant objects.
Hyperopia (Farsightedness)
hyperopia eye illustration Hyperopia (farsightedness) occurs when imperfections of the eye cause light rays to bend and converge at a point behind the retina. This causes blurred vision when viewing objects that are close, such as a book.
Astigmatism
astigmatism eye illustration Astigmatism occurs when imperfections of the eye cause light rays to bend but fail to converge at any one point. This causes various degrees of blurred vision.