Eye Care - Toric Contactlenses
Astigmatism
is a common visual distortion caused by an irregularly shaped cornea. The
surface of the cornea is toric, oblong in shape like a rugby ball, instead of
perfectly round like a football. Light rays passing through an oblong cornea bend
unequally, causing two focusing points. Consequently, vision is blurred at most
distances.
Astigmatism is usually hereditary, although factors, such as low light levels
and too much work done close up can contribute. Over time this condition may
increase slowly, but generally over a lifetime it remains relatively stable.
Forty-five percent of people who require vision correction have some degree of
astigmatism. Symptoms include squinting, occasional headaches and eye strain.
In most cases, astigmatism is accompanied by myopia or hyperopia
For the
past two decades, millions who have an astigmatism believed they could never
wear soft contact lenses. And, many who were fitted for toric lenses for
astigmatism often found the performance unsatisfactory. If you are one of them,
we urge you try soft toric lenses.
While the first toric lenses for astigmatism were not always successful,
advances in technology have improved the toric lens. With the help of
computer-aided manufacturing techniques, lens manufacturers can create toric lenses
with more than one curvature and with differences in thickness on opposing
sides of the same lens. In fact, polymers developed by contactlens companies enable
production of exceptionally thin, yet highly durable toric lens. Lathe cutting,
cast molding or a combination of both consistent and stable vision throughout
the day. The large quantity of choices
ensures a precise fit.