Toric Contact Lenses for Astigmatism
By Nancy Del Pizzo
and Liz Segre;
reviewed by Dr. Joseph T. Barr
On this page:
See also:
Have you been told you can't wear soft contact lenses
because you have astigmatism?
Or were you told that contact lenses for astigmatism called "toric" contacts didn't
come in disposable, frequent replacement, multifocal, or colored varieties?
All that was once true, but not today. Unless you have an especially complex prescription,
your astigmatism can probably be corrected with soft contacts, and you have many options.
What Are Toric Contact Lenses?
Toric contact lenses are made from the same materials as regular ("spherical") contact lenses, so they can
be either soft or RGP. The difference is in the design of the lens.
Toric lenses have two powers in them, created with curvatures at different angles (one for astigmatism, the
other for either myopia
or hyperopia).
There's also a mechanism to keep the contact lens relatively stable on the
eye when you blink or look around. To provide crisp vision, toric contact lenses cannot rotate on your eye.
Toric Contact Lens Cost
Properly fitting a toric lens takes more of your eyecare practitioner's
time and requires more expertise than regular contacts. Consequently you can expect that a fitting for torics will be more expensive than a regular contact lens fitting.
The lenses themselves also cost more than spherical lenses.
Options for Mild Astigmatism
If you have a small amount of astigmatism, between zero
and 1.00 diopter (either +1.00 or -1.00), you may be
able to wear a regular spherical RGP or even a spherical soft lens.
How can you see well if there is no power for astigmatism? With RGPs, the lenses' rigidity can help mask a need for
an astigmatic correction, because your cornea will to some degree conform to the
shape of the lens. With soft contact lenses, some
eye care professionals choose to fit you with a higher powered spherical soft lens to mask a small astigmatic correction.
The results of this technique vary from one patient to the next, which is why the fitting process may take some trial and
error by both the doctor and the patient.
Also, some lenses are available that may reduce the spherical aberration of your
eye (that exists along with the myopia or hyperopia, and astigmatism). This
type of lens may help some people who have astigmatism to see better without the necessity of a toric lens.
Spherical lenses have the same power all around the lens, so it doesn't matter
if the lens rotates on your eye. Toric lenses have two different powers in the lens,
so they must remain in position for best visual acuity. Some toric lenses are heavier
(ballasted) at the bottom to keep from rotating.
Soft or RGP?
A small percentage of patients will find that they prefer RGPs over soft contacts. Because rigid lenses
retain their shape on the cornea
better than soft lenses, they tend to provide crisper vision to people who have
astigmatism. This degree of difference in crispness is not noticeable for most contact lens wearers,
but if you're particularly fussy about your vision, you may appreciate it.
Color, Disposable, and Multifocal Toric Choices
Many brands of soft toric lenses are available today, so your eyecare practitioner can choose the brand with the best
characteristics for your particular eyes. Torics are available as frequent replacement,
disposable and even daily disposable lenses. Toric
silicone hydrogel lenses for 30-day wear are
also available.
Torics are also available in many colors that either change or enhance your natural eye color. Some colors are available as
disposables; but most colored torics are non-disposable, conventional contact lenses.
Multifocal torics
correct for presbyopia.
These are generally non-disposable as well. There are some
soft toric multifocal brands, but often an RGP lens is prescribed in this instance.
|