We are happy to provide you with some basic information on several common vision conditions.

Amblyopia

Amblyopia, commonly called lazy eye, occurs when one eye develops differently than the other eye. As a result one eye is weaker than the other. Sometimes a difference in focusing ability causes one eye to be used more often. Other times, misalignment of the eyes causes one of the eyes to “shut off” to avoid double vision. Regardless of the cause, the result is a weakened, or amblyopic, eye.

Symptoms
It’s hard to spot amblyopia. Sometimes a child will noticeably favor one eye over the other. Another possible symptom is the child frequently bumping into things on one side. The best way to tell if your child has lazy eye is through a complete exam around six months and three years. Early diagnosis can prevent amblyopia from leading to more serious problems such as loss of the ability to see three dimensions or functional blindness in the amblyopic eye.

Treatment
Most of the time amblyopia can’t be entirely corrected. The amblyopic eye will always be a bit weaker than the other. However, with treatment, vision in the amblyopic eye can be improved to some extent. Treatment involves encouraging the weak eye to develop. This is done using eye patches, vision therapy, glasses, and usually a combination of the three. The strong eye may be patched to encourage the weak eye to develop. Vision therapy can help to correct improper use of the eyes. If a focusing error is at the root of the problem, then glasses may reduce the error. Most of the time the amblyopic eye will always require glasses.

Recommended Link
National Eye Institute Amblyopia Resource Guide

Astigmatism

Sometimes the cornea is irregularly shaped causing the eye to focus an object on two different areas of the retina. This is known as astigmatism. For the cornea to bend light correctly it should be dome-shaped like a basketball. Astigmatic corneas are shaped more like a football. This causes a distorted view when looking at objects which are close-up and far away.

The cause of astigmatism is unknown. Astigmatism is often associated with myopia or hyperopia, and usually occurs from birth. Mild astigmatism usually doesn’t need to be corrected. Eyeglasses, contact lenses, or refractive surgery can correct moderate to high degrees of astigmatism.

Recommended Link
American Optometric Association: Astigmatism

Computer Vision Syndrome

Computer vision syndrome (CVS) affects three out of four computer users. It is a series of symptoms related to extended periods of computer usage. Though it is no cause for panic measures can be taken to relieve symptoms of CVS.

Symptoms
CVS can appear as a variety of symptoms. Headaches, eye strain, neck and back aches, sensitivity to light, blurred vision, double vision, and dry or irritated eyes are all possible problems related to CVS.

Risk Factors
Any computer user can develop CVS. Your vision, your computer, and the environment where you use your computer are all factors which can lead to CVS.

Recommended Link
Healthy Computing Articles: Computer Vision Syndrome

Emmetropia

When an eye’s optical power is perfectly matched to its length, the eye is said to be emmetropic. Emmetropia is the medical term for 20/20 vision needing no corrective lenses, contact lenses, or reading glasses. It occurs because the optical power of the eye can perfectly focus an image to the retina, giving them “perfect” vision. Just because lenses are not required to give good vision doesn't mean that regular health examinations should be avoided. Consult your eye care professional for their recommendation of how often you should have your eyes examined.

The opposite of emmetropia is ametropia. With ametropia, the focal point of the eye is some distance in front of or behind the retina.

Hyperopia

Hyperopia is more commonly known as farsightedness. As the name suggests people with farsightedness are able to focus on objects that are further away but have difficulty focusing on objects that are very close. This is because the eyeball is shorter than normal which prevents the crystalline lens in the eye from focusing correctly on the retina. About 25% of the population is afflicted with hyperopia. 

Hyperopia does have a genetic link. Often babies are born with hyperopia but they can usually outgrow the condition as the eye develops into the correct shape.

Hyperopia can be corrected with eyeglasses or contact lenses. There are also new surgical procedures that can correct hyperopia.

Recommended Link
American Optometric Association – Hyperopia 

Myopia

Myopia is the medical term for what is commonly referred to as nearsightedness. It is a condition where you can see objects clearly only when they are closer, but when objects are further away you can’t focus on them. Myopia usually develops in early childhood, though it sometimes develops in early adulthood. In rare cases, myopia can lead to more serious conditions such as retinal detachment.

Myopia is considered a genetic disorder. If your parents are nearsighted, you are at greater risk of also being nearsighted. 

Myopia can be accommodated and sometimes corrected with eyeglasses or contact lenses. Sometimes myopia continues to gradually worsen throughout life. Myopia can also be corrected by refractive laser surgery.

Recommended Link
American Optometric Association – Myopia 

Presbyopia

When a person reaches their 40s, a condition called presbyopia can set in. Presbyopia is the inability to focus on objects near the eye. One usually notices that it is harder to read or use the computer. Progressive lenses, Multifocal contact lenses, Monovision, Bifocals or reading glasses are used to help patients read or see clearly up close. 

Presbyopia is a natural consequence of the aging process. There is no cure though researchers are constantly looking for one. Even if someone has never had vision problems before they can still develop presbyopia. It may seem to occur suddenly but actually occurs over a long period of time. Symptoms include having to hold things at arm’s length to see them clearly, eye strain, fatigue, and headaches from near work.

Recommended Links American Optometric Association – Presbyopia