Nearsightedness, or myopia, affects up to 90 percent of children in some parts of Asia and typically progresses with age. It develops when the eye is too long, making it difficult to focus light from distant objects on the retina. Standard prescription lenses can correct the defocus but do not cure nearsightedness, and they do not slow progression rates as children grow. But recent work by David Troilo and colleagues at the State University of New York College of Optometry (U.S.A.) offers a potential cure for myopia by using specialty contact lenses that coax the eye to grow in a way that can correct vision while reducing myopia progression. They presented their work at October’s Frontiers in Optics meeting.
These special contact lenses alter how light is focused in the peripheral retina and induce changes in growth that help reshape the eye. Regular glasses or contact lenses create slight farsightedness in the peripheral retina. This peripheral farsightedness may worsen myopia in children because their eyes grow to move the retina to where the light is focused, lengthening the eye even further. The experimental lenses use different focal powers within a single lens: either alternating focal powers across the lens or confined to the outer edge. Experiments with the new lenses found that they changed eye growth and refractive state, or focus, in a predictable way—reducing the elongation of the eye that causes myopia progression.