Myopia, what most of us refer to as nearsightedness, means you can’t clearly see objects that are far away (such as road signs). It’s the most common cause of poor vision that can be corrected with eyeglasses or contact lenses in people younger than age 40 — and it’s a growing issue. 

Today, nearly 42 percent of Americans are nearsighted, up from 25 percent in 1971, according to the National Eye Institute. And the rates continue to increase. By 2050, up to 49 percent of the world’s population is expected to have myopia. That’s according to a 2016 Australian review that analyzed 145 studies involving 2.1 million people.  

In other words, if you’re nearsighted, you have a lot of company. 

Lately, myopia has been making headlines. You may have heard about an “epidemic” of nearsightedness among children. Or that too much screen time or too little outdoor time boosts the risk. Or that a growing number of treatments — beyond eyeglasses or contact lenses — may help correct your distance vision, prevent the progression of myopia, or even allow you to see clearly without wearing eyeglasses at all. 

But the most important thing to know is that myopia shouldn’t be ignored. Left untreated, it can cause eyestrain, squinting, and headaches. Not to mention the inconvenience and potential safety hazards of not being able to see important things, such as notes on the classroom blackboard or a soccer ball hurtling down the field toward you.  

Use this guide to better understand this eye condition, what causes it, and when to see your optometrist. 

What is myopia? 

Myopia is an eye-focusing problem. It happens when the front-to-back length of the eye is too long or when the cornea (the clear outer layer of the front of the eye) is too curved. In these situations, light entering the eye doesn’t focus where it should: on the light-sensing retina at the back of your eye.  

“Instead, light focuses in front of the retina, so objects at a distance do not look sharp and clear,” explains Lyndon Wong, OD. Dr. Wong is an optometrist with North Carolina Primary Vision Care Associates, PLLC, in Mooresville, located within America’s Best Contacts & Eyeglasses. 

Is myopia an eye disease? 

No. Myopia is what eye doctors call a “refractive error” — a focusing problem. It’s usually addressed with eyeglasses or contact lenses that shift the focal point of light inside the eye to where it belongs: on the retina. It’s corrected, not “treated” as a disease would be. 

But it’s important to know that high myopia may increase your risk for vision-threatening problems, such as a detached retina (because the retina is put under extra strain). High myopia is defined as myopia with a refractive error of greater than –6, according to the Cleveland Clinic. Warning signs for retinal detachment include flashes of light in one or both eyes, sudden “floaters” in your vision, loss of peripheral (side) vision, or a “shadow” over your vision. Call your eye doctor immediately if you have any of these warning signs. Surgery can fix retinal detachment if it’s caught early. 

People with high myopia may also have a higher risk of glaucoma and cataracts. Getting regular, comprehensive eye exams will let your optometrist check for these conditions. 

Who gets myopia? 

Myopia usually begins in childhood. Three out of four cases are diagnosed between ages 3 and 12. It can worsen throughout childhood and adolescence as the eyes continue to grow, then it usually stabilizes, according to Dr. Wong. But adults may also develop myopia. In some cases, it may develop due to cataracts (clouding and yellowing of the lens in the eye) or uncontrolled diseases such as diabetes. 

Did you know that kids with vision problems should get their eyes checked every year? Now’s the time to book an appointment!  

What causes myopia — and can it be prevented?  

The trigger for myopia in children and teens isn’t fully understood, but researchers have some theories. One idea is that myopia may develop if an eye-muscle problem prevents the eyes from expanding normally as the child grows. As a result, the clear lens at the front of the eye may not stretch into its proper shape and can’t focus properly, according to the National Eye Institute. 

Risk for myopia or a tendency toward myopia can be inherited. It’s more common in people who have a first-degree relative, such as a parent or sibling, with the condition. But behavior also plays an important role. For a long time, experts thought that too much “near work,” such as reading, watching TV, or using a computer, was a culprit.  

More recent research suggests that spending less time outdoors in natural light seems to be a key factor. The theory is that a young child’s eyes develop in response to exposure to natural light — and as children spend more time indoors, they may be missing out on eye-development cues they would typically get from simply being in sunlight. 

A 2021 study looked at myopia rates in children in China. It compared rates in 2020, when stay-at-home orders due to the coronavirus pandemic kept children out of school for several months, to rates in 2015 to 2019. The myopia rates were as much as three times higher in 2020 compared with the earlier years, depending on the age of the children. 

In kids who were 6, 7, or 8, the rates went up the most dramatically. The increases in myopia for the older children in the study, those ages 9 to 13, were “minimal,” according to the researchers. That led them to speculate that younger children’s eyes may be especially sensitive to outdoor light early in the growth and development of their eyes. “Children aged 6 to 8 years may be experiencing an important period for myopia development,” they noted. 

One interesting and important point, especially if you’re worried about the effect of screen time on your child’s vision: Spending less time outside seemed to be a much more important factor in myopia. “Given the fact that the younger children were assigned fewer online learning tasks than the older ones, it is unlikely that rapidly progressing myopia in younger children was caused by more intense screen time or near work,” the researchers wrote in their study. 

What can parents do with this information? According to the National Eye Institute, “the best prevention for myopia in children is more time outdoors.” But it’s still important to take breaks from screen time and up-close work, which experts think do still play a role in the development of myopia.  

“When you’re working at your computer or using your smartphone, tablet, or watching TV, take a break every twenty minutes or so,” Dr. Wong says. “Look around the room and look out a window so your eyes can focus on things at a distance.”  

Experts call this the 20-20-20 rule: For every 20 minutes of screen time, take 20 seconds to look up and focus on something that’s 20-feet away. 

“And don’t hold screens too close to your eyes,” he adds. “To find the right distance, make a fist, then check the length from your fist to your elbow. That’s how far your screens, including your phone, should be from your eyes when you’re looking at the devices,” Dr. Wong says. 

What are the symptoms of myopia?  

Schedule an eye exam with your optometrist if you notice any of these myopia warning signs in yourself or your child: 

• Far-away objects look blurry, but close-up objects look clear 
• Having eyestrain and/or headaches 
• Squinting to see clearly 
• Feeling tired while driving or playing sports due to the effort of focusing 

Other warning signs include needing to sit close to the TV, the screen in a movie theater, or the front of the classroom, or holding things close to your face to see them. Kids and teens with myopia may have declining grades, a short attention span, or rub their eyes or blink a lot. 

How is myopia diagnosed? 

During your comprehensive eye exam, your optometrist will test your vision as you read the letters on an eye chart at the other end of the room. He or she will measure how your eyes focus light with a lighted tool called a retinoscope. It checks how light bounces off your retina. This can be used to diagnose nearsightedness as well as farsightedness (the condition when your near vision is not clear).  

Your doctor will use a phoropter to check the refractive error of your eyes. This is a device that has a series of lenses to determine your final prescription. You will look through two different lenses. Your doctor will ask you which one gives you clearer vision.  

Based on your answer, your doctor will try two more lenses. (This is the well-known, Is it better with option one or option two? part of an eye exam.) They will keep refining until they’ve determined the prescription that gets you as close to 20/20 vision as possible. 

Your child’s pediatrician will check their eyes at every visit. The pediatrician should recommend an eye exam by an optometrist if vision problems such as myopia run in your family.  

Even better: Schedule an eye exam for your school age child in addition to the pediatrician’s screening. A good rule of thumb is to have your child’s eyes examined by an optometrist:  

• Around age 5, as they’re beginning to enter school 
• Every year throughout their school years 
• As directed if a vision problem is diagnosed  

How is myopia corrected? 

Most of the time, eyeglasses and contact lenses are used to refocus light and bring distant objects into sharp focus. But other options are available for adults and children. These include:

Surgery. This is an option for adults only (21 and older). Refractive surgery uses laser light beams to reshape the cornea so that light focuses as it should without the need for corrective lenses. Depending on your specific case, your doctor might suggest laser-assisted in situ keratomileusis (LASIK), which reshapes the inner layers of the cornea; laser-assisted subepithelial keratectomy (LASEK), which reshapes the outer layers of the cornea; or photorefractive keratectomy (PRK), which removes the cornea’s outer layer, called the epithelium, to reshape the cornea. (The epithelium then grows back.) 

Lens implants. If you have severe myopia and/or aren’t a good candidate for refractive surgery, lens implants may be an option. You can have phakic intraocular lenses implanted in your eyes in front of your natural lenses, or have new intraocular lenses implanted to replace your natural lenses (again, adults only). 

Contact lenses that slow myopia. Several types of contact lenses and eyeglasses are used to slow the progression of myopia in children: 

• Orthokeratology lenses: Worn at night, “ortho-k” lenses reshape the cornea so that light focuses in front of the retina for better distance vision. In 2021, Johnson & Johnson’s Acuvue® Abiliti™ lenses were the first overnight orthokeratology contact lenses to win FDA approval. While the child sleeps, the lenses reshape the cornea to improve light focusing within the eye. 
• Daytime contact lenses: In 2019, the FDA approved MiSight®, the first contact lens that slows the progression of myopia in children 8 to 12. The soft, disposable lenses are worn during the day to correct nearsightedness while also refocusing light inside the eyes in a way thought to reduce the trigger for worsening myopia. In one three-year study, children who wore the lenses had less worsening of their myopia than those who wore regular soft contact lenses, and their eyes lengthened less, according to the FDA. 
• Bifocal eyeglasses or bifocal contact lenses: These special lenses also change the way light focuses inside the eye to slow the progression of myopia. Some studies show they’re effective. In a 2020 study of special lenses worn by children with myopia for three years, researchers said results were promising, but more studies are needed.   

Eyedrops. Daily use of low-dose atropine drops can slow the worsening of myopia in kids and teens, but the treatment won’t fully correct myopia. And though the drops have FDA approval for treating amblyopia (also called lazy eye) and for use during dilated eye exams and eye surgery, they aren’t approved specifically for myopia prevention. Still, research has shown benefits in children of Asian descent, who face a high risk for myopia. Studies in diverse groups of children are underway in the U.S., so it might be worth a conversation with your child’s optometrist. 

Eye exams are an essential part of your health care routine. Book an appointment with your America’s Best optometrist today!  

Additional reading:  

Ask an Optometrist: Is There Anything I Can Do to Prevent Myopia in My Child? 

8 Signs Your Child Needs an Eye Exam 

Ask an Eye Doctor: Will My Children Inherit My Vision Problems? 

America’s Best Guide to Eye Exams 

America’s Best Guide to Contact Lenses