Refractive errors are the most frequent eye problems in the United States. They are optical defects that result in light not being properly focused on the eye's retina. Nearsightedness and farsightedness are the most common refractive errors. People with nearsightedness see near objects clearly, while distant ones are blurred. People with farsightedness experience just the opposite - distant objects are clear while near ones are blurred.
Nearsightedness, or myopia, as it is medically termed, is a vision condition in which close objects are seen clearly, but objects farther away appear blurred. Nearsightedness occurs if the eyeball is too long or the cornea, the clear front cover of the eye, has too much curvature. As a result, the light entering the eye isn’t focused correctly and distant objects look blurred.
Farsightedness, or hyperopia, as it is medically termed, is a vision condition in which distant objects are usually seen clearly, but close ones do not come into proper focus. Farsightedness occurs if your eyeball is too short or the cornea, the clear front cover of the eye, has too little curvature. As a result, the light entering the eye isn’t focused correctly and near objects look blurred.
The symptoms of nearsightedness and farsightedness are very similar, other than the obvious symptom of being able to see near or far objects.
- Distant objects appear blurry (nearsightedness)
- Near objects appear blurry (farsightedness)
- Eye Strain
- Rubbing Eyes Often
The technical cause of nearsightedness is when the eyeball is too long or the cornea has too much curvature and light is focused in front of the retina instead of directly on it. There is significant evidence that many people inherit nearsightedness, or at least the tendency to develop nearsightedness. If one or both parents are nearsighted, there is an increased chance their children will be nearsighted. Even though the tendency to develop nearsightedness may be inherited, its actual development may be affected by how a person uses his or her eyes. Individuals who spend considerable time reading, working at a computer, or doing other intense close visual work may be more likely to develop nearsightedness.
The technical cause of farsightedness is when the eyeball is too short or the cornea has too little curvature and light is focused behind the retina instead of directly on it. Farsightedness is often present from birth, but children have a very flexible eye lens, which helps the eye adjust. Most children outgrow the condition. If a child is still a bit farsighted when the eye has stopped growing (at around 9 years of age), the eye can usually adjust to make up for the problem. But as we age, our eyes can no longer adjust as well, and farsightedness becomes more obvious. Farsightedness also often runs in families. In rare cases, some diseases such as retinopathy and eye tumors can lead to farsightedness.
A comprehensive optometric examination is the best way to detect near or farsightedness. Testing for near or farsightedness may use several procedures in order to measure how the eyes focus light and to determine the power of any optical lenses needed to correct the condition.
- Visual Acuity Tests
- Eye Movement Testing
- Glaucoma Testing
- Refraction Test
- Retinal Examination
- Slit-lamp Examination
There are a number of options for patients seeking effective treatment of nearsightedness or farsightedness, from time-tested eyeglasses to the latest in laser technology. Choosing the right treatment for you will depend on a number of factors, including your lifestyle, medical history, and degree of refractive error.
An eye specialist can prescribe eyeglasses or contact lenses that correct nearsightedness or farsightedness by bending the visual images that enter the eyes, focusing the images correctly at the back of the eye. If your condition is not server, you may only need to wear glasses or contact lenses for certain activities, like watching a movie or driving a car. However, if your condition is advanced, they may need to be worn all the time.
For those patients with severe nearsightedness or farsightedness, glasses and contact lenses may not correct the problem. In those cases laser vision correction may be the best solution. Laser vision correction
as the name implies, uses lasers to reshape the cornea of the eye and correct the refractive error. Laser vision correction is a widely accepted treatment for severe nearsightedness or farsightedness. LASIK and PRK are both types of laser vision correction.