What is myopia?
People who have myopia (also known as nearsightedness) have difficulty seeing distant objects, but can see objects that are near clearly. For example, a person who is nearsighted may not be able to make out highway signs until they are just a few feet away.
Myopia affects a significant percentage of the population. It’s an eye focus disorder that is easily corrected with eyeglasses, contact lenses or surgery.
How common is myopia?
Myopia is very common. According to the American Optometric Association, more than 40% of Americans are myopic, a number that is rapidly rising, especially among school-aged children. Eye experts expect this trend to continue in the coming decades.
Today one in four parents has a child with some degree of nearsightedness. Some eye experts believe that if your child spends an extraordinary amount of time engaged in “near” activities, such as reading or using smartphones and computers, it may raise the risk of developing myopia.
Can myopia lead to blindness?
Usually, myopia is a minor nuisance that can be corrected with eyeglasses, contact lenses or surgery. But in rare cases, a progressive type called degenerative myopia develops that can be very serious and is a leading cause of legal blindness. Degenerative myopia affects only about 2% of the population. It is believed to be inherited and is more common in Jewish, Japanese, Chinese and Middle Eastern people.
Symptoms and Causes
What causes myopia?
If you have myopia, more than likely at least one or both of your parents did, too. Eye experts are still unsure of the exact cause of myopia, but believe it to be a mix of hereditary and environmental factors. It’s possible that you can inherit the ability to be myopic and then if your lifestyle produces just the right conditions, you’ll develop it. For example, if you use your eyes for a lot of close-up work, such as reading or working on a computer, you may develop myopia.
Myopia usually appears in childhood. Typically, the condition levels off, but it can worsen with age. Because the light coming into your eyes is not focused correctly, images appear to be unclear. Think of it a little like a misdirected spotlight. If you shine a spotlight on the wrong spot in the distance, you won’t be able to see the right object clearly.
What is refractive error?
When the shape of your eye doesn’t allow light to focus correctly on the retina, eye experts call this a refractive error. Your cornea and lens work together to bend light onto your retina, the light sensitive part of the eye, so that you can see clearly. If either your eyeball, cornea or your lens isn’t the right shape, light will bend away from or not focus directly on the retina as it normally would.
If you are nearsighted, your eyeball is too long from front to back, or your cornea is too curved or there are problems with the shape of your lens. Light coming into your eye focuses in front of the retina instead of on it, making faraway objects look fuzzy.
When an eye care provider develops your eyeglass prescription for nearsightedness, it will be a negative number, depending upon your degree of nearsightedness, such as -2.00. The higher the number, the stronger your lenses will be.
What are the symptoms of myopia?
If you are nearsighted, you may notice:
- Faraway objects look blurred or fuzzy.
- Close items appear clear.
- Eye strain.
- Tiredness when driving, playing sports or looking more than a few feet away.
Some additional symptoms of myopia to watch for in your children include:
- Poor school grades.
- Shortened attention span.
- Holding objects close to the face.
Most cases of myopia are mild and easily controlled with eyeglasses, contact lenses or refractive surgery. However, in rare cases more severe disorders develop.
High myopia: A rare inherited type of high-degree nearsightedness is called high myopia. It happens when your child’s eyeballs grow longer than they should or the cornea is too steep. High myopia is usually defined as myopia with a refractive error greater than -6. It can progressively worsen to higher powers of myopia. High myopia usually stops getting worse between the ages of 20 and 30. It can be corrected with eyeglasses or contact lenses, and in some cases, refractive surgery, depending on severity. High myopia may raise your child’s risk of developing more serious sight conditions later in life, such as cataracts, detached retinas and glaucoma. Left untreated, high myopia complications can lead to blindness, so regular eye exams are critical.
Degenerative myopia: A fairly rare but serious form that usually begins in early childhood is degenerative myopia. This form is severe because it damages the retina and is a leading cause of legal blindness.
Does myopia get worse with age?
Yes, it can. Especially during growth spurts of the pre-teen and teen years, when the body grows quickly, myopia can get worse. At the age of 20, myopia usually levels off. It’s also possible for adults to be diagnosed with myopia. When this happens, it’s usually due to visual stress or a disease like diabetes or cataracts.
Visual stress can be caused by spending too much time doing up-close activities, such as reading or doing computer work. Eye experts believe that your focusing muscles may get stuck in “near gear” from overusing them this way.
If you are an adult experiencing sudden nearsightedness, floaters (sort of like spots floating through your field of vision), flashes of light or shadows, or sudden sight loss in one eye, contact an eye care provider immediately to rule out a more serious health condition.
Diagnosis and Tests
How is myopia diagnosed?
Your eye care provider can diagnose myopia using standard eye exams. Myopia is usually diagnosed in childhood but can develop in adults as a result of visual stress or diabetes.
Adults. Your provider will test how your eyes focus light and measure the power of any corrective lenses you may need. First your provider will test your visual acuity (sharpness) by asking you to read letters on an eye chart. Then he or she will use a lighted retinoscope to measure how light is reflected by your retina. Your provider will use also use a phoropter. A phoropter is an instrument that measures the amount of your refractive error by placing a series of lenses in front of your eyes. This is how your provider measures the lens strength you need.
Children. Your pediatrician will check your child’s eyes at each well child visit. A first eye exam should be before age 1, if possible. If your child has no evident eye problems, then schedule a repeat eye exam before kindergarten. Since myopia runs in families, if your child has family members with vision issues, it’s even more important to test eyes early. If you or your or your pediatrician notice any vision issues, your child may be referred to an optometrist or pediatric ophthalmologist.
During a children’s eye exam, your eye care provider will do a physical examination of your child’s eyes and check for a regular light reflex. For children between the ages of 3 and 5 years, your provider will also conduct vision screenings using eye chart tests, pictures, letters or the “tumbling E game,” also called the “Random E’s Visual Acuity Test.” Since your child’s vision continues to change as he or she grows, continue to make sure they get vision screenings by a pediatrician or eye care provider before first grade and every two years thereafter. While most schools conduct eye screenings, they are usually not complete enough to diagnose myopia. About three quarters of nearsighted children are diagnosed between ages 3 and 12.
The American Optometric Association recommends comprehensive eye exams to catch vision conditions early when they can be more easily controlled for both children and adults.
Management and Treatment
How is myopia treated?
Glasses or contact lenses can correct myopia in children and adults. For adults only (with rare exceptions for children), there are several types of refractive surgeries that can also correct myopia.
With myopia, your prescription for glasses or contact lenses is a negative number, such as -3.00. The higher the number, the stronger your lenses will be. The prescription helps the eye focus light on the retina, clearing up your distance vision.
- Eyeglasses. The most popular way for most people to correct myopia is with eyeglasses. Depending on the degree of vision correction needed, you will wear eyeglasses either daily — or only for when distance vision is needed. You may only need glasses for driving. Some kids with myopia may only need glasses to play ball, watch a movie or view the chalkboard. Some people may need to wear glasses constantly to see clearly. A single-vision lens will make distance vision clearer. But patients over 40 who have myopia may require a bifocal or progressive lens to see clearly both near and far.
- Contact lenses. Some people find that their distance vision is sharper and wider with contact lenses. A potential downside is they require more care to keep clean. Ask your provider which type might be right for your myopia level and other refractive errors.
- Ortho-k or CRT. Some people with mild myopia may be candidates for temporary corneal refractive contact lenses that you wear to bed to reshape the cornea temporarily, long enough to see for your daily activities.
- LASIK is a laser-assisted in situ keratomileusis procedure, the most common surgery to correct nearsightedness. In a LASIK procedure, your ophthalmologist uses a laser to cut a flap through the top of the cornea, reshape the inner corneal tissue and then drops the flap back into place.
- LASEK is a laser-assisted subepithelial keratectomy procedure. In a LASEK procedure, your ophthalmologist uses a laser to cut a flap through only the top layer (epithelium) of the cornea, reshapes the outer layers, and then closes the flap.
- PRK is short for photorefractive keratectomy, which is a type of laser eye surgery used to correct mild or moderate nearsightedness, and may also be used to correct farsightedness and/or astigmatism. In a PRK procedure your ophthalmologist uses a laser to reshape the surface of your cornea, which flattens it and allows light rays to focus on the retina. Unlike LASIK, the ophthalmologist does not cut a flap. PRK is preferred for patients with corneas that are thinner or have a rough surface because it disrupts less corneal tissue than a comparable LASIK surgery.
- Phakic intraocular lenses are an option for patients who have high myopia or whose corneas are too thin for PRK or LASIK. Phakic intraocular lenses are placed inside the eye just in front of the natural lens.
- Intraocular lens implant allows your ophthalmologist to surgically insert a new lens in your eye, replacing your natural one. This procedure is done before a cataract develops.
- Vision therapy is an option if your myopia is caused by spasms of your focusing muscles. You can strengthen the muscles through eye exercises and improve your focus.
How can you prevent myopia from getting worse?
Though there’s no cure for myopia, there are everyday steps you can take that can support your overall eye health. These days, it’s especially important to set limits for your children (and yourself) on activities that lead to eye strain.
Try these sight-saving tips:
- Limit time on digital devices.
- Take screen breaks to stretch your eye muscles.
- Don’t read or work in dim light.
- Encourage going outdoors.
- Wear sunglasses outside.
- Wear protective eye gear for sports/hobbies.
- Stop smoking.
- Schedule regular eye exams.
- Ask your provider about atropine eye drops to slow progression.
- Ask your provider about dual focus contact lenses to slow progression in kids.
Remember, don’t let your or your child’s eyes get stuck in “near gear” from spending too much time on computers or smartphones. Get outside. Make going to the park a regular family outing. Walk the dog. Get out there and have fun.
Which foods should my family eat to keep eyes as healthy as possible?
Everyone’s eyes rely on nutrients from the foods we eat to maintain vital eye tissues and functions. Nutrition is especially essential to your child’s vision as their eyes grow and develop. In addition to limiting caffeinated colas, keep everyone hydrated by drinking enough water.
Also try to eat foods that are rich in:
- Vitamin A. You need enough of the antioxidant vitamin A in your diet (or through a supplement) to maintain the surface of your eyes and healthy vision. There are vitamin A-rich sources for every diet preference. Plant-based choices include vegetables like sweet potato, leafy green vegetables and carrots. Or you may choose animal-based foods, such as cheese, oily fish or liver.
- Vitamin C. The best foods for getting a daily dose of vitamin C are fruits and vegetables, including oranges, grapefruit, strawberries and broccoli.
- Lutein. Eat leafy green vegetables to make sure to get enough lutein, which helps eyes filter harmful blue light that can damage retinas.
You can supplement your or your child’s diet with a multivitamin if you think you aren’t getting enough. Remember though that vitamins that come in a pill are not as well absorbed by the body as those that occur naturally in fresh foods.
Try these recipes to get the right vitamins onto your family menu:
- Recipe: Baked Cajun Sweet Potato Fries
- Sweet Potato-Lime Salad
- Tossed Green Salad with Simple Vinaigrette
Taking good care of your family’s vision means regular eye exams, a good eye care routine and a healthy diet. Keeping those healthy habits will help you all to see a future filled with all the things you love.