There has been a long-standing debate on what causes people to become nearsighted (myopia). The two leading theories are: 1) Genetic; and 2) Environmental causes. Here I’ll give explanations of both potential causes and why they both factor in to cause changes in your vision.
Approximately 90% of myopic (nearsighted) individuals have at least one parent who is also nearsighted. Twins also have a higher degree of inheritability v. non-twin siblings. Researchers have also found that parental onset of myopia (when the parent was first diagnosed nearsighted) is an excellent indicator of when their children will first need glasses or contacts. Studies also show that parental myopia is a good indicator of how their children’s myopia will progress.
Even with this evidence, there is still not a single gene that has been found to be responsible for nearsightedness. Most likely, multiple genes are involved with the development of myopia and its progression.
Evidence of an environmental cause of nearsightedness is best explained by a study of an Eskimo population that has essentially no myopia within parents or grandparents; however children that are being formally educated have a high prevalence of nearsightedness (nearly 3 out of 5 children were myopic). This and other similar studies suggest a potential epidemic of myopia that will affect us more and more as we increase the amount of time spent on near activities (especially our reliance on computers).
What can you do?
Current and past therapies for myopia progression (and / or halting the progression of myopia) have had mixed results. Doctors have experimented with bifocal glasses, rigid gas permeable contacts, and drug therapy. Currently, the only therapy with studies to prove any significant slowing of myopia progression is Corneal Refractive Therapy, or CRT. CRT is a procedure that uses specially designed therapeutic contact lenses that gently reshape the cornea while you sleep. This reshaping has the added benefit of providing clear vision throughout the day without contacts or glasses. It has been proven safe and effective for people of all ages. The lenses effectively act as a retainer to slow the progression of myopia.
So What Does This Mean To You And Your Family?
Most likely, no study will provide definitive evidence that one theory alone can fully explain how people become nearsighted. Environmental and genetic causes may play integrated roles in the development of myopia. Until we can isolate a cause, and potentially a cure, I will keep you updated on the best possible ways to correct your vision.
Author: Dr. Matthew Skrdla
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