Common Vision Problems
What are the most common vision problems?
The eye functions very much like a camera. The front part of the eye--the cornea and lens--focus light onto the back of the eye, or retina. This is very similar to how the lens of a camera focuses light onto the film inside the camera. Once the retina receives an image, it transmits a signal to the brain, via the optic nerve, for the image to be developed. The most common vision problems are refractive problems. This means that the shape of your eye does not bend, or refract, the light coming into the eye properly so the image sent to the brain looks blurry.
The most common problems include:
- nearsightedness (myopia)
- farsightedness (hyperopia)
- the loss of close reading vision (presbyopia)
- astigmatism, or distorted vision
What is nearsightedness?
Nearsightedness is a vision condition that allows clear viewing of close objects, but distant objects are out of focus. It occurs when the eyeball is too long or when the outer layer of the eye, called the cornea, has too much curvature. This causes light rays to focus at a point in front of the retina instead of directly on it. A sign of nearsightedness may be squinting to see road signs clearly. A nearsighted child may not be able to read the chalkboard at school or to watch TV without sitting very close. Nearsightedness may be helped with glasses, contacts, or LASIK surgery.
What is farsightedness?
Farsightedness is a vision condition that allows clear viewing of distant objects, but close objects are out of focus. It occurs if the eyeball is too short or the cornea has too little curvature. This causes light rays to focus behind the retina instead of directly on it. Some signs of farsightedness include blurry vision when looking at objects up close. You may also notice eyestrain, fatigue, aching or burning eyes, and headaches after doing close work (such as reading or needlework). Often babies are born with a slight farsightedness that clears up as they grow and their eyeballs become longer. Children with farsightedness may not be interested in reading or they may have trouble concentrating because they cannot keep close objects in focus. Farsightedness may be helped with glasses, contacts, or LASIK surgery.
What is presbyopia?
Presbyopia is similar to farsightedness. It is a condition that occurs as a natural part of the aging process. You usually start noticing this change in your early to mid-forties. A loss of elasticity of the lens of the eye results in an inability to bring close objects into focus. Some signs of presbyopia include blurred vision at normal reading distance and the tendency to hold things at arm's length to read them, as well as eye fatigue and headaches when doing close work. Contacts are sometimes used for presbyopia. However, it is often easier for people who already wear contacts to get reading glasses that magnify close-up objects.
What is astigmatism?
Astigmatism is vision that is distorted or blurred. With this vision problem, the normally round cornea is not round. This prevents light from focusing properly on the retina. Astigmatism causes far and near vision to be distorted and blurry. Astigmatism is usually present at birth. Mild astigmatism may cause headaches, eyestrain, fatigue, or blurred vision but may not require glasses or contacts. Severe astigmatism requires correction with glasses or contacts. Astigmatism may also be treated with LASIK surgery.
When should I see my eye care provider?
See your eye care provider if you are concerned about your vision. The American Academy of Ophthalmology recommends that you have a complete eye exam according to the following schedule:
- Ages 20 to 29: at least once during this time
- Ages 30 to 39: at least twice during this time
- Ages 40 to 64: every 2 to 4 years
- Age 65 or older: every 1 to 2 years
If you have a family history of certain diseases such as glaucoma or if you have medical problems such as diabetes, more frequent visits may be recommended, even if you are not having any eye symptoms.
Reviewed for medical accuracy by faculty at the Wilmer Eye Institute at Johns Hopkins. Web site: http://www.hopkinsmedicine.org/wilmer/
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Published by RelayHealth.
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