Astigmatism

• What is an Astigmatism?
• Is an Astigmatism a disease?
• Can Spectacles help?

What is an Astigmatism?

The human eye is seldom perfect. Astigmatism causes blurred vision by preventing a point focus of objects seen through the lens system of the eye and is a very common part of most spectacle prescriptions..

Astigmatism is usually caused by the shape of the front surface of the eye (the cornea) but may also be due to the lens inside the eye being slightly tilted. These are normally inherited characteristics.

A simple magnifying glass focuses light to a sharp point. This is because the two surfaces of a magnifying lens are spherical, each similar in shape to the back of a soup spoon. Now imagine a lens with surfaces shaped like the back of a table spoon, which has a different curvature in the direction of the handle compared with that across the spoon. A lens of this shape would cause light to focus between two different spots giving an elongated image rather than a single, sharp point. This system is described as "astigmatic", which means "not a point"./P>

Is an Astigmatism a disease?

Astigmatism is not a disease, or particularly unusual. Regular eye examinations are sensible because uncorrected astigmatism can interfere with concentration as well as comfort in visual tasks requiring accuracy.

Can Spectacles help?

Spectacles and some contact lenses will correct the blurred vision caused by astigmatism. Some people wearing their first spectacle correction for astigmatism may find an unexpected change in the size and shape of objects which affects their judgment of distance. This visual disturbance might only be a feeling of being taller or shorter, but may be more dramatic with floors seeming to slope up or down and walls appearing to curve in or out. In most cases it takes only a few days to get used to these distortions, but sometimes it may take several weeks.

Spectacles will not make astigmatism worse, they merely allow the wearer to see more clearly and comfortably and their use is not habit forming. For some very young children wearing spectacles is most important if vision is to develop normally.

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