Ortho K is a program that uses specially designed rigid gas permeable contact lenses to decrease myopia and astigmatism without surgery. Ortho K contact lenses reshape the cornea, the front surface of the eye, to change the power or prescription of the eyes. Ortho K lenses also act as a retainer to decrease the progression of myopia in children. Ortho K can also improve small amounts of farsightedness by steepening the cornea.
Ortho K lenses are usually worn only while sleeping. Once the desired correction has been reached, no contact lenses need to be worn during the day because the cornea retains the shape and power determined by the Ortho K lenses. A retainer lens must be used each evening, or several times a week to maintain the desired correction. Ortho K lenses allow freedom from glasses or contact lenses during waking hours while playing sports, driving, swimming, etc.
In mild cases of myopia, correction to 20/20 can take just a few hours. In higher degrees of myopia and astigmatism, it can take a few months to reach the desired correction. In both cases, retainer lenses need to be worn to maintain the corrected vision. Ortho K lenses can be modified to reflect your new prescription when your prescription changes naturally over the years.
The cornea makes up approximately two-thirds of the focusing power of the eye. Ortho K lenses change the prescription of your eye by changing the shape and curvature amount of the cornea to focus images on the retina, or “movie screen” of your eyes.
To design Ortho K lenses, and to monitor treatment progress, we use a corneal topographer that maps your cornea using thousands of points. Several lenses are usually necessary to achieve the desired result.