About 25 percent of people in the United States are nearsighted, according to the National Eye Institute. Also called myopia, nearsightedness is a vision condition in which the person sees distant objects as blurred.
Specifically, nearsightedness is a refractive error. In normal vision, the cornea and lens of the eye refracts incoming light, sending it to the retina. But if the cornea is curved too much, the light does not refract properly, resulting in nearsightedness.
Having an eye that is longer than normal can also cause blurry vision for objects in the distance, noted the MayoClinic.com.
Both children and adults can be nearsighted, and the visual condition affects both men and women equally. The National Eye Institute noted that the disorder is frequently diagnosed in people between the ages of 8 and 12, with a possible worsening during patients’ teenage years.
Certain people have a higher risk of developing nearsightedness. For example, a person with a parent who is nearsighted has a higher risk of developing the condition. People who were born prematurely may have a higher risk, as they are more likely to have ocular conditions that affect eye shape, according to the MayoClinic.com.
In addition to seeing objects in the distance as blurry, patients may have headaches that result from eyestrain. Patients may squint in order to see clearly. A child who is nearsighted may need to sit close to blackboard in school, hold her books very close to her face when she is reading, or rub her eyes frequently. She may also blink excessively or appear to be unaware of objects in the distance.
A person who is showing these signs should get her eyes checked. During the eye exam, the ophthalmologist will test the person’s eye pressure, color vision and visual acuity. In the test of visual acuity, a person who is nearsighted will do well on the Jaeger eye chart, which checks for vision up close, but will display trouble on the Snellen eye chart, which checks for vision at a distance.
If the ophthalmologist determines that the person has nearsightedness, she may recommend eyeglasses or contact lenses. A refraction test will be used to determine what prescription is correct. For some people, they may require refractive surgery, in which the surgery alters the shape of the cornea.
MedlinePlus noted that the most common surgery used is LASIK, or laser-assisted in-situ keratomileusis. Patients should discuss with their doctor which treatment option is best for them.
References
MedlinePlus Medical Encyclopedia. Nearsightedness. Web. 28 November 2011
http://www.nlm.nih.gov/medlineplus/ency/article/001023.htm
MayoClinic.com. Nearsightedness. Web. 28 November 2011
http://www.mayoclinic.com/health/nearsightedness/DS00528/METHOD=print
National Eye Institute. Nearsightedness. Web. 28 November 2011
http://www.nei.nih.gov/healthyeyes/myopia.asp
Reviewed November 28, 2011
by Michele Blacksberg RN
Edited by Jody Smith