Myopia occurs if the eyeball is too long or the cornea (the clear front cover of the eye) is too curved. As a result, the light entering the eye isn't focused correctly, and distant objects look blurred. Myopia affects nearly 30% of the U.S. population.
While the exact cause of myopia is unknown, there is significant evidence that many people inherit myopia, or at least the tendency to develop myopia. If one or both parents are nearsighted, there is an increased chance their children will be nearsighted. Even though the tendency to develop myopia may be inherited, its actual development may be affected by how a person uses his or her eyes. Individuals who spend considerable time reading, working at a computer, or doing other intense close visual work may be more likely to develop myopia.
It is estimated that by 2050, half of the world—about 4.75 billion people—will have myopia. This eye condition is the most common cause of distance-related vision problems.
Myopia is a kind of refractive error—an eye disorder that affects the way light refracts within the eye. In an eye without myopia, light is focused onto the surface of the retina, and an image is conveyed to the brain via the optic nerve. An eye with myopia has a bit of trouble focusing light in the same way. That’s because a myopic eye is typically elongated, rather than resembling a perfect sphere. Or, its cornea may be a bit more steeply curved than normal. These myopic aspects of the eye cause light to focus on a point in front of the retina, rather than directly on it. And light that doesn’t hit the retina produces an unclear image in the brain.
People with myopia can have difficulty clearly seeing a movie or TV screen, a whiteboard in school or while driving. Generally, myopia first occurs in school-age children. Because the eye continues to grow during childhood, it typically progresses until about age 20. However, myopia may also develop in adults due to visual stress or health conditions such as diabetes.
Scientists haven’t yet isolated exactly what causes myopia. We know that it runs in families—you’re more likely to be nearsighted if one or both of your parents are, too. But, in addition to genetics, environmental factors seem to play a role. Children who spend less time outside appear to be more prone to developing myopia, whereas those who spend more time outdoors have their risk of myopia reduced. Scientists speculate that a lack of exposure to bright sunlight may be what’s slowing the progression of myopia, but they don’t know exactly how this relationship functions.
A January 2021 study supports this theory, showing that COVID lockdowns—and the increase in time spent indoors by children ages 6–8—upped the prevalence of myopia by 1.4 to 3 times.
Our Experts Eye Doctors can test for myopia during a comprehensive eye exam. First, they’ll test your unassisted visual acuity by having you read lines from a Snellen chart—that’s the big poster with rows of letters and numbers that get smaller as they go down the page. They’ll also have you look through a tool called a phoropter, which is fitted with several lenses. The doctor will lower sets of lenses in front of each of your eyes and ask you which lenses help you to see more clearly. They may use a couple more specialized tools, such as a retinoscope and/or autorefractor, to determine the strength of your eye prescription. Both of these tools shine a light into the eye and help the doctor to assess the degree of your myopia.
People with myopia have several options available to regain clear distance vision. They include:
People with myopia have a variety of options to correct vision problems. Our Expert Eye Doctor will help select the treatment that best meets the visual and lifestyle needs of the patient.