Michael Cole, OD, Child and Family EyeCare Center
The myopia (nearsightedness) epidemic is increasing across the world at a rapid pace. In a recent study of first-year college students, researchers saw a rise in myopia from 23.4 percent of students in 2002 to 41.3 percent in 2014. While the growth in these numbers are staggering, the good news is that recent innovation and research has brought about some great tools for reducing the amount of yearly change in myopia which we call “myopia control.”
The term myopia means that when light enters the eye, it is not focused clearly on the retina, where the photoreceptors are located. Instead, light rays reach a focal point in front of the retina, and when the light rays continue to their destination, they are out of focus and blurry. These light rays are easily refracted into focus in the correct position using glasses, contact lenses, and even surgical procedures, such as LASIK.
So, if it is simply a question of optics, why do our children get more and more myopic each year? The eyeball itself gets longer. When the eye grows, the light is again focused in the wrong position, and it requires even more correction than before to refocus the light correctly again. This tends to occur until late teens or early 20s when an individual is fully grown.
How do we stop it? Treatments designed to curb the progression of myopia are aimed at slowing the elongation of the eyeball itself. A few different methods have risen to the top as the best way to reduce the stimulus for the eye to grow longer. Each of these methods utilize specific types of contact lenses.
The best option for myopia control is the use of Ortho-K contact lenses. Ortho-K contact lenses are rigid contact lenses that are specifically designed to gently reshape the cornea when worn. This reshaping of the eye is temporary and lasts for a day or two after removal of the lenses. These are worn only at night, and the cornea is molded during sleep. So, great vision can be enjoyed without any daytime contact lens wear at all. This type of correction has been shown to greatly reduce the amount of elongation of the eye when utilized, thus reducing the need for stronger lenses in the future.
Another type of contact lens that has been proven effective is a multi-focal contact lens with a distance-center design. Multi-focal contact lenses are normally used after age 40 to help when focusing our eyes up close becomes troublesome. These lenses are worn like a traditional contact lens, inserted upon waking up in the morning, taken out at night, and discarded either monthly or daily, depending on the lens. While effective for myopia control, these lenses do cause our distance vision to be slightly hazy around the edges and in our peripheral vision.
We don’t have to accept increasing amounts of myopia every year as seen with traditional glasses and contact lens wear. Being proactive with myopia control options can greatly reduce the magnitude of corrective lenses that will be needed in the future.
