In our offices and around the country, optometrists are seeing a significant—and disturbing—new trend: more and more patients are presenting with myopia, or nearsightedness. People with myopia can see close-up objects clearly, but objects at a distance appear blurry.
According to the National Eye Institute, the prevalence of myopia in the U.S. population is growing quite rapidly: In 1971, the percentage of the U.S. population with myopia was 25%. Now it’s up to 42%. In Asian countries such as Japan, China, South Korea, and Taiwan, the percentage of people with myopia is 80% to 90%.
So, what’s behind this nearly doubling of nearsightedness in recent decades? And, are you and your family at risk?
What is Myopia?
Myopia is an eye condition that affects the eye’s ability to focus clearly. People with myopia—called myopes—can focus on close objects but can’t focus on distant objects.
People with myopia may experience symptoms including headaches, eye strain, and squinting the eyes to try to focus on distant objects.
For students, myopia can be the root cause of poor grades and disinterest in the classroom. Myopic students can’t see at a distance, so they may not be able to see what the teacher is writing or presenting on the classroom board. The longer a myopic student goes without vision correction, the more their school performance will suffer—both in the classroom and playing sports or games during recess.
What Causes Myopia?
Myopia is partially a hereditary condition. Children of parents with myopia are more likely to develop it. However, there is evidence that environmental and lifestyle factors are impacting the sharp rise in myopia.
While there are other contributing factors, experts agree that the rise in digital screen use plays a significant role in the epidemic of myopia worldwide. When the human eye is “taught” to practice focusing up-close on a screen for hours each day, the eye adapts to being able to do so. What suffers as a result of that adaptation is the ability to focus clearly at a distance.
How Eye Shape Impacts Vision
Did you know that the length and curvature of your eyeball impact your ability to focus? If your cornea is too curved, the eye’s point of focus shifts, resulting in clear close-up vision and blurred distance vision.
Similarly, when the eyeball grows longer from front to back, it becomes pear-shaped rather than round. Because of the excess length, the point of focus moves from being exactly on the light-sensitive retina to being just in front of the retina. That makes objects in the distance seem blurry.
It doesn’t take much of an eye elongation to have a big effect on vision. A typical adult eye is 24 millimeters in length from front to back. That size doesn’t vary much, even among age, gender, and racial differences. In the average myopic adult, however, the eye is longer: about 25 millimeters. That small variation causes a big difference in the eye’s focal point.
How To Treat Myopia
Myopia is a refractive condition. That means it impacts how and where light is focused in relation to the highly sensitive tissue of your eye’s retina, where light should be focused. The retina is located on the back wall of the eye. In myopia, since the eyeball is longer than normal, the light focuses just in front of the retina, causing nearsightedness.
Like other refractive conditions, myopia is treatable with corrective lenses. These include contact lenses and prescription glasses that shift the focal point back to the retina and improve distance vision.
However, there is concern that children and teens are being diagnosed with myopia at earlier and earlier ages. This condition, progressive myopia, may continue to advance throughout their lives.
Some experts believe that slowing down the rate of progressive myopia development may benefit the overall visual system. People with advanced degrees of myopia, called “high myopia,” may be more at risk of developing other eye conditions and diseases, including glaucoma, cataracts, retinal detachment, and myopic macular degeneration.
We believe that the early onset of myopia in children is related to excessive digital screen use. To slow the progression of myopia, it’s a best practice to minimize kids’ screen time.
If you or your student are myopic, talk with your optometrist about options to correct or treat this potentially progressive refractive eye condition. Taking steps to slow the progression of myopia in your student may benefit his or her overall eye health in the future.
One important step in managing myopia is to schedule an annual comprehensive eye exam with your optometrist so we can track its progression and make sure you are seeing your best. Call us today to schedule your annual eye exam!