Special contact lenses could potentially stop myopia from progressing
By Ben Coxworth
October 3, 2012
For younger readers with perfect eyesight, here’s something you might not know – glasses and contact lenses don’t do anything to cure nearsightedness, they only help compensate for it. In fact, the wearer’s vision often continues to deteriorate as they age. Now, however, a team of scientists have developed special contact lenses that they claim can halt the condition if it’s caught in childhood.
Nearsightedness, more properly known as myopia, is a result of the eye becoming too long. This causes light from distant objects to be focused slightly in front of the retina, instead of right on it. The result is that things that are far away appear out of focus.
Glasses and contact lenses bring those objects back into focus, by helping to once again focus light onto the retina. However, according to David Troilo, a biomedical scientist at the State University of New York College of Optometry, there’s a trade-off. He claims that while corrective eyewear does indeed correct myopia by focusing light on the center of the retina, it actually causes a small amount of hyperopia (farsightedness) in the peripheral retina.
As a nearsighted child grows, says Troilo, their eye can actually lengthen even farther in an attempt to compensate for the peripheral hyperopia caused by their eyewear. This, unfortunately, just results in the myopia getting even worse.
Working with colleagues at the university, he has created contact lenses that don’t cause the peripheral hyperopia. They do this by incorporating different focal powers within a single lens, either alternating across its surface, or confined to its outer edge. When tested, the contacts “successfully reduced the elongation of the eye that causes myopia progression.”
Troilo says that several versions of the lenses may soon be available for use on young patients.