Orthokeratology is a safe, non-surgical contact lens procedure to reduce or eliminate nearsightedness (myopia) and astigmatism, dramatically improving the natural vision. The Ortho-K procedure was developed in 1962 and has provided corrective eye care to thousands of patients through the therapeutic use of contact lenses.
Like all human systems, the visual mechanism is subject to defects. Most of these defects, however, can be optically corrected with eye glasses and contact lenses, and are not related to disease. In the same sense that teeth may be straightened by the use of braces, structural irregularities of the eye (refractive errors) can be reduced or eliminated by the use of special contact lenses.
Before proceeding further with our discussion on Orthokeratology, it might be of help to more fully understand the operations of a normal eye, and the possible refractive errors.
First we need to know what is normal. In a visual system with no refractive error there is, for every point is space, a focusing of the point on the retina (the light sensitive portion of the eye).
In a nearsighted eye (Myopia), instead of the light focusing to a point on the retina, it is brought to a focus at a point in front of the retina. When the light reaches the retina, instead of producing a point, there is a blurred circle, resulting in poor vision. Myopia is a common problem in young children, adolescents, and college students.
In the case of farsightedness (Hyperopia), instead of the light rays focusing on the retina, they would come to a point behind the retina.
The third refractive error is astigmatism. This is a condition in which there is more than one point of focus for a point in space. Curvature of the cornea is usually the primary cause of astigmatism.