Nearsightedness (Myopia)

Topic Overview

What is nearsightedness?

Nearsightedness (myopia) is a common cause of blurred vision. If you are nearsighted, objects in the distance appear blurry and out of focus. You might squint or frown when trying to see distant objects clearly. View a photo as seen through a normal and a nearsighted eye .

Nearsightedness is usually a variation from normal, not a disease. Less often, nearsightedness happens because of another disease or condition.

What causes nearsightedness?

Most nearsightedness is caused by a natural change in the shape of the eyeball that makes the eyeball oval (egg-shaped) rather than round. Less often, nearsightedness may be caused by a change in the cornea or the lens.

These problems cause light rays entering the eye to focus in front of the retina . Normally, light focuses directly on the retina. See a picture of the parts of the eye .

What are the symptoms?

The main symptom of nearsightedness is blurred vision when looking at distant objects. You may have trouble clearly seeing images or words on a blackboard, movie screen, or television. This can lead to poor school, athletic, or work performance.

You may think your child is nearsighted if he or she squints or frowns or holds books or other objects very close to his or her face. Children who are nearsighted may sit at the front of the classroom or very close to the TV or movie screen. They may not be interested in sports or other activities that require good distance vision.

How is nearsightedness diagnosed?

A routine eye exam can show whether you are nearsighted. The eye exam includes questions about your eyesight and a physical exam of your eyes. Ophthalmoscopy, tonometry, a slit lamp exam, and other vision tests are also part of a routine eye exam.

Eye exams should be done for new babies and at all well-child visits.¹ Nearsightedness most commonly begins in childhood or in the early teens (between the ages of 8 and 14), so it is usually first discovered in children of grade-school age.

Nearsightedness can be mild, moderate, or high.

How is it treated?

Eyeglasses or contact lenses can help correct nearsightedness. Surgery can also be done to change the shape of the cornea or to implant artificial lenses in the eyes to reduce or fix nearsightedness.

Frequently Asked Questions

Health Tools

Health Tools help you make wise health decisions or take action to improve your health.

	Decision Points focus on key medical care decisions that are important to many health problems.
	Should I have laser surgery for nearsightedness?

Cause

Most nearsightedness (myopia) is caused by a natural change in the shape of the eyeball that makes it egg-shaped rather than round. This causes light to focus in front of the retina rather than directly on the retina. Nearsightedness is usually inherited. A child is likely to be nearsighted if one or both parents are nearsighted.

See more information about eye anatomy and function.

Many people have believed for a long time that too much close work, such as reading or sitting too close to the television, causes nearsightedness. One study suggested that people who have jobs that involve large amounts of reading do indeed have higher degrees of nearsightedness.²

Other than the natural change in the shape of the eyeball, there are a few rare causes of nearsightedness. These are:

• Pathological myopia, in which the back of the eyeball continues to grow longer after reaching normal adult size.
• Secondary myopia, which may develop as a result of many conditions, including premature birth and a number of eye diseases.
• Pseudomyopia, or sudden nearsightedness that rapidly gets worse because of an underlying cause, such as uncontrolled diabetes.

In some cases, nearsightedness may be caused by eye problems such as cataracts and keratoconus. Premature birth may increase the likelihood that a baby or young child may become nearsighted, especially if the baby has retinopathy of prematurity (ROP).

People who are very nearsighted (severely myopic) have an increased risk of glaucoma and retinal detachment. Retinal detachment happens because the retina may be stretched if you have severe myopia.

Symptoms

Nearsightedness (myopia) causes blurred vision. If you are nearsighted, you may have:

• Trouble seeing objects that are far away.
• Trouble seeing the blackboard, television, or movie screen.
• Reduced school or athletic performance.

Children younger than age 8 or 9 may not realize that they have trouble seeing objects far away. Parents or teachers may suspect nearsightedness when a child:

• Squints or frowns.
• Holds books or objects very close to the face.
• Sits at the front of a classroom or theater or close to the TV or computer.
• Is not interested in sports or other activities that require good distance vision.
• Gets headaches regularly.

What Happens

Nearsightedness (myopia) usually begins in childhood or the early teens, between the ages of 8 and 14. Most children are born slightly farsighted, but this is corrected by the normal development of the eyeball during childhood. But if the eye grows so long that light rays focus in front of the retina instead of directly on it, the child becomes nearsighted.

• During the teen years, as the eyeballs continue to grow, nearsightedness may develop or get worse quickly. Teenagers may need new glasses every 12 months or even more often.
• Nearsightedness usually stops getting worse by age 14 to 16 in women and by the mid-20s in men.
• Most nearsightedness stabilizes at a mild to moderate level.

You cannot change the course of nearsightedness after the condition starts. You can only try to correct your vision with glasses, contact lenses, or surgery.

Although treatment cannot change its course, it is important to detect nearsightedness as soon as possible. Children with uncorrected nearsightedness may have trouble learning in school and building social skills, and they may develop self-esteem problems.

After age 40, people often develop presbyopia, an inability to focus on near objects. This may require bifocal glasses or contact lenses.

Nearsightedness increases the risk of a serious condition called retinal detachment, although the risk is still quite low. The increase in risk depends on the degree of nearsightedness you have. Severe nearsightedness increases the risk much more than mild nearsightedness. People who have pathological myopia have an increased risk of cataracts and glaucoma as well as retinal detachment.

What Increases Your Risk

Asians and people who have a family history of nearsightedness are at increased risk for nearsightedness. Women have a greater risk for high myopia, or severe nearsightedness, than men do.

Premature babies, especially babies who have retinopathy of prematurity, are more likely to develop nearsightedness. A number of inherited eye and other diseases increase the risk of nearsightedness.

Research has indicated a link between close work, such as reading, and the development and progression of nearsightedness. One study showed that people in professions that involve extensive reading have higher degrees of nearsightedness.²

When To Call a Doctor

If you have a sudden change, loss, or disturbance in your vision or you have pain in your eye or yellow or greenish discharge from your eye, see the topic Eye Problems, Noninjury to evaluate your symptoms. You may need immediate care.

Whether you are nearsighted (myopic) or not, doctors recommend having routine eye exams throughout life (see Early Detection in the Exams and Tests section of this topic). In addition to these routine exams, call your doctor if:

• Your child or teenager has symptoms of nearsightedness or any complaints of unclear vision.
• Existing nearsightedness in an adult suddenly becomes worse.
• You have a change in your ability to tolerate your contact lenses (for example, you can no longer wear them for the usual periods of time).
• You see flashes of light, floaters, change in your side vision, or dimming of your vision (these may mean you have retinal detachment).

Watchful Waiting

Watchful waiting is not appropriate if you think that you or your child is developing nearsightedness. Although treatment cannot change its course, it is important to detect nearsightedness as soon as possible.

Identifying and treating nearsightedness early may prevent children from having trouble in school and in social settings. If you think that you or your child is nearsighted, see an eye care specialist.

Who To See

Eye care specialists who can diagnose eye problems and prescribe corrective lenses include:

• Ophthalmologists.
• Optometrists.

Health professionals who can perform screening exams to detect vision problems and refer you to an eye care specialist include:

• Pediatricians.
• Family medicine physicians.
• Internists.
• Nurse practitioners.
• Physician assistants.

To prepare for your appointment, see the topic Making the Most of Your Appointment.

Exams and Tests

A routine eye exam can detect nearsightedness (myopia) and other vision problems and diseases that can affect the eyes. A complete exam takes 30 to 60 minutes.

A routine eye exam includes:

• Questions about your medical history and a physical eye exam.
• Vision tests, which include tests for visual acuity, visual fields, and refraction.
• A slit lamp exam, which is an exam of the eye using a microscope.
• Tonometry, which measures the pressure inside your eye.
• Ophthalmoscopy, which allows a doctor to see inside the back of the eye.

Early Detection

Routine testing of the ability to see details and shapes clearly is usually a part of every general physical exam during childhood. Children younger than age 5 should have screening for the eye diseases amblyopia and strabismus and defects in visual acuity.³ See information about when to schedule eye exams with an eye care specialist for:

• Children and infants.
• Teenagers.
• Adults.

Treatment Overview

Although nearsightedness (myopia) cannot be cured, treatment can restore normal or near-normal vision.

Most people who are nearsighted simply wear glasses or contact lenses to correct their vision. This is the standard treatment for nearsightedness. But you may choose to have surgery to correct your vision.

• Corrective lenses refocus light entering the eye on the retina. Eyeglasses and contact lenses are the treatment of choice for most people with nearsightedness. Both are safe and effective and are less risky and less expensive than surgery. Some people find that eyeglasses do not provide the same quality of central or side vision as contact lenses. And while contacts can provide excellent vision, they do carry a risk of infection and therefore require regular cleaning and maintenance. Prescriptions for eyeglasses and contact lenses specify both the shape and power of the lens.
• Surgery changes the shape of the cornea. Several procedures are available, such as LASIK, photorefractive keratectomy, corneal ring implants, and intraocular lens implants (IOLs). See the Surgery section of this topic for more information.

See a general listing of the advantages and disadvantages of:

• Eyeglasses.
• Contact lenses.
• Surgery.

What To Think About

No single treatment is right for everyone who is nearsighted. Consider the following general points in deciding which option is right for you:

• How predictable are the results (how reliably does the treatment provide the exact amount of correction needed)?
• How stable are the results? Does the correction change over time?
• What are the risks and potential complications?
• How much maintenance and self-care are needed?
• How convenient is the option? What is the cosmetic effect (that is, how does it look on you)?
• Age can be a factor. In the United States, some surgical procedures are not approved for people younger than 18 years of age. In people younger than 20, the eyes may still be changing (refractive instability).
• The laser surgical procedures most commonly used to correct nearsightedness cause permanent changes in the eye. They cannot be reversed. Newer options such as corneal ring implants or intraocular lens implants (IOLs) can be removed if needed.
• What is the cost of treatment? Will insurance cover it?

Other considerations may affect your choice of treatment.

• Will the treatment affect your work or career? Some jobs (an aircraft pilot, for example) may not allow certain corrective treatments. Be sure to check with your employer or a professional organization or society in your field before you make a decision.
• If you actively participate in contact sports-such as boxing, football, wrestling, or martial arts-in which blows to the head, face, and eyes can occur, talk to your doctor about which treatment will work best for you.
• Certain health conditions and medicines may affect the outcome of surgical treatments. For example, autoimmune or immunodeficiency diseases and some medicines may prevent proper healing after surgery. Other conditions, such as pregnancy, diabetes, or use of steroid medicines, may cause changes in vision.
• Certain conditions in the eyes may affect your choice of treatment. For example, people who have a history of glaucoma, keratoconus, inflammatory eye diseases, herpes simplex keratitis, or past eye injuries or surgeries should avoid surgery to correct nearsightedness.

Should I have laser surgery for nearsightedness?

If you decide to have surgery, make sure you choose a surgeon who has low complication rates or extensive experience in performing the type of surgery you will have. Studies suggest that complications are not as likely to occur after surgery performed by an experienced surgeon as after surgery performed by a surgeon with less experience.⁴

Prevention

Although nearsightedness (myopia) is easily treated, it cannot be prevented, nor can you keep it from getting worse when you have it. It often gets worse, sometimes rapidly, until the late teens or early 20s, when it usually stabilizes. Nearsightedness does not improve as you get older.

Many people believe that too much close work, such as reading or sitting too close to the television, causes nearsightedness. But there was little evidence to support this belief. However, one study suggested that people in professions that involve extensive reading have higher degrees of nearsightedness.²

Special diets, eye exercises, and medicines will not treat or cure nearsightedness.

Home Treatment

You cannot prevent or cure nearsightedness (myopia), but you can work with your eye specialist to correct it. See:

• Tips for general good vision, such as taking periodic breaks from visually demanding tasks.
• Tips on contact lens care, including always rinsing your lens storage case and letting it air-dry to avoid contamination.

After refractive surgery to correct nearsightedness, home care may be needed.

• You may need to wear an eye patch, bandage, or special contact lenses for a few days after surgery. Do not rub your eye after surgery.
• Your doctor may prescribe eyedrops to reduce inflammation and the risk of infection. You may need to use them for several days or months after surgery.
• For 2 weeks after surgery, you should avoid vigorous sports, eye makeup, and activities that get water in the eye. The surgeon may recommend that you shower before the surgery and then avoid showering for a day or two afterward to keep from getting water in the eye.
• Depending on the type of surgery, your vision may be reduced for several days afterward. Do not drive until your vision has cleared.
• Dry-eye symptoms are common but usually temporary. They can be treated with lubricating eye drops. If the problem persists, you can use plugs that close off the ducts that drain the eye. Or your doctor may prescribe medicines for dry eye symptoms.

Medications

Medicines are not used to correct nearsightedness (myopia).

Surgery

Several types of surgery for nearsightedness (myopia) are available to change the shape of the cornea and refocus light directly on the retina . However, surgery cannot correct pathological myopia.

The goal of surgery is to allow people who are nearsighted to see clearly without corrective lenses or to be less dependent on corrective lenses. Most doctors consider 20/40 vision or better after surgery a satisfactory result. People with 20/40 vision or better are allowed to drive a car without corrective lenses. Overall, most people who have surgery achieve 20/40 vision or better after surgery.

Laser surgeries include:

• LASIK (laser in-situ keratomileusis), which is currently the most commonly used corrective surgery for nearsightedness in the United States. LASIK has a high success rate and low complication rate for low to moderate nearsightedness. It may also be used to correct more severe nearsightedness. In general, it requires less healing time, is less painful, and offers a faster visual recovery than photorefractive keratectomy (PRK).
• PRK (photorefractive keratectomy) and LASEK (laser epithelial keratomileusis), which are similar surgeries. They are another type of corrective surgery for nearsightedness that is used frequently. Like LASIK, PRK and LASEK have high success rates and low complication rates for low to moderate nearsightedness. They may be used instead of radial keratotomy (RK) to correct severe myopia.

RK (radial keratotomy)

Radial keratotomy (RK) is very successful and safe for people who have mild to moderate nearsightedness (less than 3 diopters). Although it is still used in some cases, it has been replaced in most cases by LASIK and PRK.

Corneal ring implants

This type of surgery to correct mild nearsightedness was approved by the U.S. Food and Drug Administration (FDA) in 2004. It uses corneal ring implants to change the shape of the cornea.

Intraocular lens implants

Intraocular lens implants (IOLs) may be used to correct severe myopia. IOLs, also called implantable contact lenses (ICLs), have been shown to be a safe and effective means of correcting moderate to severe myopia.⁵

Surgery Choices

Laser surgery for nearsightedness changes the shape of the cornea to refocus light directly on the retina. There are three main types of laser surgery used to treat nearsightedness.

LASIK (laser in-situ keratomileusis) makes a small flap in the cornea and removes some of the tissue exposed by the flap.

PRK (photorefractive keratectomy) and LASEK (laser epithelial keratomileusis) use a laser to reshape the cornea. The laser is applied to the cornea after the surface layer has been removed.

Radial keratotomy (RK) uses several incisions on the cornea to change the curve of the cornea over the pupil.

Other types of surgery for nearsightedness involve the surgical placement of implants to either change the shape of the cornea or replace or assist the eye's natural lens.

Corneal ring implants are clear pieces of acrylic that can be surgically implanted to flatten the cornea and reduce nearsightedness.

Intraocular lens implants replace the eye's natural lens with a clear plastic implant.

What To Think About

Of the three main types of refractive surgery, RK has been in use the longest time, but PRK and LASIK are now more commonly used. Studies suggest that laser surgery such as PRK and LASIK is at least as accurate as radial keratotomy (RK) and has less risk of overcorrection or troublesome side effects. But some people may choose to wait for more information about the long-term outcomes of laser surgery before they decide to have it.

If you find that glasses or contact lenses are inconvenient, surgery to correct nearsightedness may be appropriate. But nearsightedness is not a disease, and a nearsighted eye is otherwise normal and healthy.

Weigh your desire to have clear vision without glasses or contacts against the risks of surgery. Ask your eye doctor any questions about surgery that you have (for example, what are the risks, benefits, possible outcomes, and alternatives to surgery) so that you have a good understanding of your options and can make the best decision.

Should I have laser surgery for nearsightedness?

Other Treatment

No other treatment (such as medicines, diet, eye exercises, or other self-help measures) has been shown to reverse nearsightedness.

Other Places To Get Help

Online Resource

Organizations

Related Information

• Eye Problems, Noninjury
• Farsightedness (Hyperopia)

References

Citations

1. American Academy of Pediatrics, et al. (2003, reaffirmed 2007). Policy statement: Eye examination in infants, children, and young adults by pediatricians. Pediatrics, 111(4): 902-907.

2. Fredrick DR (2002). Myopia. BMJ, 324(7347): 1195-1199.

3. U.S. Preventive Services Task Force (2004). Screening for visual impairment in children younger than age 5 years: Recommendation statement. Rockville, MD: Agency for Healthcare Research and Quality. Available online: http://www.ahrq.gov/clinic/uspstf/uspsvsch.htm.

4. Wilson SE (2004). Use of lasers for vision correction of nearsightedness and farsightedness. New England Journal of Medicine, 351(5): 470-475.

5. Implantable Contact Lens in Treatment of Myopia (ITM) Study Group (2003). U.S. Food and Drug Administration clinical trial of the implantable contact lens for moderate to high myopia. Ophthalmology, 110(2): 255-266.

Other Works Consulted

• Trobe JD (2006). Physician's Guide to Eye Care, 3rd ed. San Francisco: American Academy of Ophthalmology.

• Yanoff M, Duker JS, eds. (2004). Ophthalmology, 2nd ed. St. Louis: Mosby.

Credits