Myopia (Nearsightedness)

What is nearsightedness?

Nearsightedness, also known as myopia, is a common type of refractive error where close objects appear clearly, but distant objects appear blurry.

Symptoms

Nearsightedness symptoms may include:

• Blurry vision when looking at distant objects
• The need to squint or partially close the eyelids to see clearly
• Headaches caused by eyestrain
• Difficulty seeing while driving a vehicle, especially at night (night myopia)

Nearsightedness is often first detected during childhood and is commonly diagnosed between the early school years through the teens. A child with nearsightedness may:

• Persistently squint
• Need to sit closer to the television, movie screen or the front of the classroom
• Seem to be unaware of distant objects
• Blink excessively
• Rub his or her eyes frequently

What Causes Myopia?

Myopia occurs when the eyeball is too long, relative to the focusing power of the cornea and lens of the eye. This causes light rays to focus at a point in front of the retina, rather than directly on its surface.

Nearsightedness also can be caused by the cornea and/or lens being too curved for the length of the eyeball. In some cases, myopia is due to a combination of these factors.

Myopia typically begins in childhood and you may have a higher risk if your parents are nearsighted. In most cases, nearsightedness stabilizes in early adulthood but sometimes it continues to progress with age.

Risk factors

Certain risk factors may increase the likelihood of developing nearsightedness, such as:

• Family history. Nearsightedness tends to run in families. If one of your parents is nearsighted, your risk of developing the condition is increased. The risk is even higher if both parents are nearsighted.
• Reading. People who do a lot of reading may be at increased risk of myopia.
• Environmental conditions. Some studies support the idea that a lack of time spent outdoors may increase the chances of developing myopia.

Complications

Nearsightedness may be associated with several complications, such as:

• Reduced quality of life. Uncorrected nearsightedness can affect your quality of life. You might not be able to perform a task as well as you wish. And your limited vision may detract from your enjoyment of day-to-day activities.
• Eyestrain. Uncorrected nearsightedness may cause you to squint or strain your eyes to maintain focus. This can lead to eyestrain and headaches.
• Impaired safety. Your own safety and that of others may be jeopardized if you have an uncorrected vision problem. This could be especially serious if you are driving a car or operating heavy equipment.
• Other eye problems. Severe nearsightedness puts you at a slightly increased risk of retinal detachment, glaucoma and cataracts.

How is nearsightedness corrected?

Nearsightedness can be corrected with eyeglasses, contact lenses, or surgery.

Eyeglasses are the simplest and safest way to correct nearsightedness. Your eye care professional can prescribe lenses that will correct the problem and help you to see your best.

Contact lenses work by becoming the first refractive surface for light rays entering the eye, causing a more precise refraction or focus. In many cases, contact lenses may provide clearer vision, wider field of vision, and greater comfort. They are a safe and effective option if fitted and used properly. However, contact lenses may not be the best option for everyone.

If you certain eye conditions you may not be able to wear contact lenses. Discuss this with your eye care professional.

Refractive surgery aims to permanently change the shape of the cornea which will improve refractive vision. Surgery can decrease or eliminate dependency on wearing eyeglasses and contact lenses. There are many types of refractive surgeries and surgical options should be discussed with an eye care professional.

When to see a doctor

If your difficulty clearly seeing things that are far away is pronounced enough that you can't perform a task as well as you wish, or if the quality of your vision detracts from your enjoyment of activities, see an eye doctor. He or she can determine the degree of your nearsightedness and advise you of your options to correct your vision.

Seek emergency medical care if you experience a sudden onset of flashes of floaters or a shadow covering part of your field of vision. These are warnings signs of retinal detachment, which is a rare complication of myopia. Retinal detachment is a medical emergency, and time is critical.