Shortsightedness, or nearsightedness, is a common visual condition in which a person can see close objects clearly, but objects in the distance appear blurry. Technically known as myopia, shortsightedness is typically caused by an unusually long eyeball, which makes light rays focus too far in front of the retina, or the back of the eye, instead of directly on the surface of the retina. Because the light is focused too early, a blurred image is left on the retina.
Shortsightedness often develops in rapidly growing school-aged children and becomes worse during the teenage years, requiring frequent changes in prescription glasses or contact lenses to maintain clear vision. Shortsightedness usually stabilizes as the body stops growing in the early twenties. A person who has developed shortsightedness may experience blurred vision, headaches, eyestrain, or frequent squinting. Uncorrected shortsightedness may cause a person to feel fatigued after driving, watching television, or playing sports.
An optometrist or an ophthalmologist can confirm diagnosis of shortsightedness during a comprehensive eye examination. The treatment for this eye condition depends upon several factors, including the patient’s age, occupation, and activities. Eye doctors most commonly correct shortsightedness with corrective lenses, such as prescription glasses or contact lenses, which compensate for the elongated shape of the eye and allow light to focus properly on the retina. Depending on the degree of shortsightedness, corrective lenses may have to be worn all the time for clear vision. If the degree of impairment is slight, however, glasses or contacts may only be necessary for activities which require distant vision, such as driving, watching TV, or reading a chalkboard.
Recently, refractive surgery has become a popular option for reducing or eliminating the need for corrective lenses. The most common type of refractive surgery is laser-assisted in situ keratomileusis (LASIK), in which the surgeon cuts a small flap in the top of the cornea, an excimer laser takes off some of the corneal tissue, and the flap is then replaced. Another form of refractive surgery is photorefractive keratectomy (PKR), in which an excimer laser removes a layer of corneal tissue to flatten the cornea. Both procedures allow light rays to focus correctly on the retina.
Eye doctors can also treat shortsightedness with orthokeratology, a non-invasive procedure which involves wearing specially-designed rigid or semi-flexible gas permeable contact lenses which slowly reshape the curvature of the cornea. The contact lenses are worn while sleeping, and when the lenses are removed in the morning, the cornea temporarily retains the new shape. This allows the patient to see clearly without any corrective lenses.
At this time, shortsightedness cannot be cured. However, a proper diagnosis, correct eye care, and consistent monitoring of the condition should help to bring things back into perspective.