ASTIGMATISM
(ah-STIG-ma-tis-um)
85-90% of all
eyeglass prescriptions contain some correction for astigmatism.
Correction for astigmatism may occur alone or may be combined with
correction of nearsightedness or farsightedness.
Uncorrected
astigmatism may cause blurred and distorted vision. Astigmatism causes annoying
symptoms of eyestrain such as headaches, eye fatigue, sensitivity to light, loss
of visual achievement and poor visual concentration.
The eye, like a
camera, has an outer curved lens to focus light. A camera lens is always
manufactured with a perfectly round curvature to focus light evenly.
The eye, however, is a "SOFT" CAMERA.
When astigmatism is present, the eye has an EGG-SHAPED or asymmetrical
front lens curvature rather than a perfect round shape.
As a result, an astigmatic eye requires a special dual-power lens to
focus light evenly.
FIRST
CORRECTION OR LARGE CHANGES IN CORRECTION OF ASTIGMATISM MAY CAUSE OBJECTS OR
STRAIGHT LINES TO APPEAR TILTED OR DISTORTED. If correction is worn as
recommended, this perception of distortion will decrease steadily with time.
Routine changes
in astigmatism are expected to occur with time. Since astigmatism tends to
progress slightly faster in later years, adults may need more frequent
prescription lens changes. Eyeglasses
and/or special astigmatic (toric) contact lenses are available to correct this
condition accurately.
For more information about astigmatism follow this link Astigmatism