HOW TO IMPROVE YOUR VISION: Orthokeratology
This information was prepared for those persons with imperfect vision who wish to function in our complex visual society without the use of eyeglasses or contact lenses and those with serious vision problems who wish to improve their unaided vision without the use of surgical procedures.
Medical science has made tremendous strides to enable us to function better within our environment. Corrective procedures are now widely used in the fields of medicine and dentistry. In addition to corrective techniques, the health sciences now fully realize the importance of prevention. If a defect can be prevented, it will obviously not need to be corrected.
The visual mechanism, like all other human systems, is subject to defects. Today, many people enjoy good vision because the field of medicine has made great strides in the treatment of eye diseases by surgery and the use of medication. Most eye defects, however, are not related to disease. They are the result of normal development problems associated with the structure of the eye or caused by the environment in which we place ourselves.
Eyeglasses or contact lenses are usually prescribed to compensate for these abnormalities. Although these devices allow us to function better, they do little or nothing to correct the underlying problem.
At one time, these irregularities were considered permanent; some of them subject to worsen with time, and no therapy was available to normalize them. Today, the situation has changed. The ocular science, Orthokeratology, provides corrective eye care through the therapeutic use of contact lenses. In the same sense that teeth may be straightened by the use of braces in dentistry, structural irregularities of the eye and their resulting refractive errors can now be reduced and vision improved by the use of specially designed contact lenses.
Orthokeratology offers the ultimate in care for contact lens wearers. It can make imperfect vision significantly and dramatically better for everyone with healthy eyes but poor vision. For those with severe refractive problems, it opens up a new world they may have never seen before without reliance on strong corrective measures.
WHAT ARE REFRACTIVE ERRORS?
We have all heard the terms nearsightedness, farsightedness, and astigmatism, but few people have actually taken the time to understand them. To appreciate orthokeratology it is important to become familiar with the principles involved in these refractive errors.
NORMAL: To begin, we must know what is normal. In an eye with no refractive error, the light is sharply focused on the retina at the back of the eye. (Fig. 1) The retina is the light sensitive portion of the eye. This is the way light must focus to have the sharpest possible vision at all distances, without strain.
NEARSIGHTEDNESS (MYOPIA): In the nearsighted eye, light focuses in front of the retina instead of upon it. (Fig. II) As a result, the myopic or nearsighted eye will give clear vision at close range but blurred vision at a distance.
FARSIGHTEDNESS (HYPEROPIA): In the farsighted eye, the focal point is behind the retina, just the opposite of the nearsighted eye. (Fig. III) In trying to focus the eye properly, the muscles within the eye must "overwork", often causing eyestrain and headaches.
ASTIGMATISM: In its simplest form, astigmatism is a refractive error which causes light to be focused upon more than one area of the retina. (Fig. IV) Astigmatism may also exist in combination with nearsightedness or farsightedness, thus producing symptoms blurred vision, eyestrain, headaches, or all of these.
WHAT ARE THE CAUSES OF REFRACTIVE ERRORS?
It is extremely important to understand that these refractive errors have nothing to do with the health of the eyes. Blurred vision caused by these problems has nothing to do with blindness. These conditions are caused by the structure of the eye and relate only to the physical development of the individual body, no less than its height, the shape of the head, and other features. The only effect of these physical differences is the clarity of the image on the retina and the amount of extra work the eye must do to see clearly. They affect the efficiency but not the health of the eye.
The basic factors that create refractive errors are:
- The overall length of the eyeball
- The curvature of the cornea
- The efficiency of the muscles relative to the demands placed upon them
Should the eyeball be longer than normal or the curvature of the cornea too great, the focal point will fall short of the retina and nearsightedness will be present. This myopic condition will usually begin in grade school and, left untreated, will worsen until normal growth stops at about age 18. Nearly 40% of the total U.S. population is afflicted with myopia.
If the eye is shorter than normal or if the cornea is too flat, the image will focus at a point behind the retina causing farsightedness. When present, this condition exists at birth and tends to decrease during the growth years. It does not affect vision as dramatically as myopia does, but with age the strain and muscle "overwork" are felt to a greater extent.
When the cornea is not round but irregular in form, such as a football, astigmatism results. Like myopia, astigmatism starts at an early age. It remains the same throughout life, but, like farsightedness, its effects are felt more as the aging process proceeds.
Since myopia occurs normally during the growth years, any worsening after the age of 18 is usually not caused by length of the eyeball or curvature of the cornea, but may be usually traced to the environment.
Individuals who do not have the muscle flexibility and efficiency to perform visual tasks at close range for long periods of time, but are forced to do so, often develop myopia. This condition is on the increase in our society since reading is so much a part of the learning process and computers are a regular work tool.
Contact Dr. Garber today to make an appointment or learn more about the future of vision correction.