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Cataract Help

Toric / Astigmatism

Toric intraocular lens

Overview

Astigmatism is a naturally occurring condition of the cornea (See photo below). Instead of being shaped perfectly round like a baseball, corneas with astigmatism are shaped more oval like a football. Most types of astigmatism can be corrected with glasses or contact lenses.

  • Toric lenses provide a clear image without glasses

  • No induced halos or other side effects

  • Can be used for distance vision, near vision or monovision

  • Procedure and recovery similar to standard surgery

Treatment Cons

The toric lens implant does NOT allow you to both read and see far away without eyeglasses. It may not necessarily correct 100% of your astigmatism either. However, compared to a conventional lens implant that does not correct astigmatism, the toric lens implant should improve how well you see without glasses, and any eyeglasses that you do require should be less strong and potentially more comfortable to wear.

Do I Still Need Glasses?

Treatment Pros

  • Insurance does not cover the whole procedure

  • Irregular astigmatism usually cannot be corrected

  • Will likely need glasses for intermediate and near objects if vision is focused for distance

Eye with astigmatism

Astigmatism in the Cornea

  • Like nearsightedness, astigmatism creates a natural blur in healthy eyes that can be corrected by wearing eyeglasses or contact lenses

  • It is common and results from an inherited, imperfect shape of the cornea

  • The cornea can be seen in the image to the right as the clear window through which you see the world

  • A cornea without astigmatism should be round, but if is more oblong (like a football) it will not focus all light in the correct spot causing your natural vision to be blurrier

  • Higher amounts of astigmatism cause the vision to be blurrier without eyeglasses and there is no advantage to astigmatism because it adds natural blur to every focal distance.

  • Toric lenses neutralize regular astigmatism leading to clearer vision

  • Irregular astigmatism often cannot be corrected

Topography and astigmatism
Image of cornea

Imaging and Measuring Astigmatism

  • Astigmatism is often measured using a topographer

  • The colorful image to the right shows astigmatism in the horizontal meridian (against the rule)

  • This astigmatism corresponds to the eye next to it

  • The TORIC LENS seen is lined up horizontally to neutralize the astigmatism

  • Look for the toric lens markings

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