Vision Information - Myopia (Short-Sightedness)
Short-sightedness - or myopia - is a vision problem in which close objects can be seen clearly but objects far away are blurred. Short-sightedness occurs if the eyeball is too long or the cornea has too much curvature. As a result, the light entering the eye can't focus correctly and distant objects appear blurred and distorted.
Short-sightedness is a common condition and affects around 30% of the U.S. population. It usually first occurs in school-age children and, because the eye continues to grow during childhood, it will progress until about age 20.
What Causes Short-sightedness?
The exact causes of the condition are unknown, but research indicates that two factors may be primarily responsible for its development:
There is significant evidence to suggest that many people inherit short-sightedness, or at least a tendency to develop it. If one or both parents are short-sighted, there is a greater likelihood their children will be short-sighted.
Even though the tendency to develop the condition may be inherited, its development may be affected by how the eyes are used. Those who spend a lot of time doing close visual work, such as reading or working in front of a computer, may be more likely to develop short-sightedness.
Symptoms of short-sightedness may also be a sign of a blood sugar condition, such as diabetes or an early indication of a developing cataract.
Diagnosis and Treatment
A comprehensive eye test, using several procedures, by your optometrist will determine if you have short-sightedness.
There are several options available for persons with short-sightedness to regain good distance vision. These are:
Eyeglasses are the primary choice for correcting short-sightedness. A single vision lens is usually prescribed to provide good vision at all distances. But patients over 40, and children or adults whose short-sightedness is due to intense close vision work may have bifocal or progressive addition lenses prescribed for them. These lenses provide different strengths or powers throughout the lens to provide for distant and close vision.
Some patients will find that contact lenses offer better vision than eyeglasses and may suit them better cosmetically. Although they provide a wider field of vision, they require regular cleaning and care to safeguard eye health.
Orthokeratology involves the fitting of a series of rigid gas permeable contact lenses to reshape the cornea. The contact lenses are worn overnight during sleep, and removed for the entire day allowing patients to go about their daily activities eyewear-free. Your optometrist can advise you further about the process and whether or not it would suit your particular requirements.
Using a laser beam of light, short-sightedness can be corrected by reshaping the cornea in a process called LASIK surgery. Although this surgery has generally proved successful, it is still a developing therapy in which some problems have occurred. Speak to your optometrist to acquire full information about this process and how it is likely to affect you.
Vision therapy is an option for patients whose blurred distance vision is caused by a spasm of the muscles which control eye focusing. Various exercises are used to improve the ability to focus and regain good vision.
People with short-sightedness have a number of options to correct their vision problem. Your optometrist will help you select the treatment that best meets your visual and lifestyle needs.