Glossary - Common Eye Disorders

Astigmatism

If an eye is astigmatic it looks more like a rugby ball in shape than a football. In the astigmatic eye, both distance and near vision are likely to be equally affected and it can be found in conjunction with both long - and short - sightedness. A toric or cylindrical (cyl) lens is used to correct astigmatism.

Cataracts

A clouding of all or part of the normally clear lens within your eye, which results in blurred or distorted vision. Cataracts are most often found in persons over age 55, but they are also occasionally found in younger people.

Diabteic Retinopathy

A complication of diabetes and a leading cause of blindness, it is a progressive disease which weakens and causes changes in the small blood vessels that nourish the eye's retina, the delicate, light sensitive lining of the back of the eye. These blood vessels may begin to leak, swell or develop brush-like branches.

Dry Eye

When eyes do not produce enough tears, or that you produce tears that do not have the proper chemical composition.

Glaucoma

An eye disease in which the internal pressure in the eyes increases enough to damage the nerve fibers in your optic nerve and cause vision loss. The increase in pressure happens when the passages that normally allow fluid in your eyes to drain become clogged or blocked. The reasons that the passages become blocked are not known.

Hypermetropia

See Long Sightedness.

Long Sightedness - Hypermetropia

The image of a distant object is focused behind the retina, because the eye may be too short or the refractive mechanism is too weak. Long sighted people generally have more difficulty with close work. In young people distance vision is usually good, but in older patients it tends to be reduced. A plus (+ ve) powered lens is required to correct long sight.

Myopia

See Short Sightedness.

Presbyopia

For people from their mid 40s, presbyopia results in a reduced ability to see or focus on close objects clearly. A plus (+) powered lens is used to correct presbyopia.

Short Sightedness - Myopia

The image of a distant object is focused in front of the retina, because the eye may be too long or the refractive mechanism is too strong. Short sighted people will have blurred distance vision, but generally good near vision. A minus (-ve) powered lens is required to correct short sight.

.