Astigmatism is an eye condition that causes blurred or double vision because the cornea is ‘out-of-round’. The cornea is the outer part of the eye where light first passes before it enters the lens. In people with astigmatism, the cornea is curved such that it is steeper along one axis than the axis 90 degrees away. Think of the side of a donut — the vertical curve is greater than the horizontal curve, and the difference between the two curvatures is … the amount of astigmatism! Astigmatism occurs in more than 80% of adults, so this is a common optical imperfection.
Astigmatism is one of those strange terms that most people don’t understand, so it sounds intimidating when you are told that you have it. It doesn’t help that prescription contact lenses cost significantly more if astigmatism is present. Let’s clear up some of this confusion.Astigmatism describes optical blur that arises when the curvature of an optical surface is “out of round”. This irregular curvature can occur on the cornea or on the lens.
Optical blurring, ghosting, slight doubling or drop-shadow effects result from having astigmatism. Most people only know they have astigmatism because their eye doctor has measured them for glasses or contacts and has told them they have this condition.
5 Ways to Correct Astigmatism
- Contact Lenses
- LASIK (corneal laser sculpting)
- Placement of arcuate incisions in the peripheral cornea, typically done at the same time as cataract and IOL surgery (also called limbal relaxing incisions or LRI). This method is best done only for relatively small amounts of astigmatism.
- Toric astigmatism-correcting IOL placement. This can be done for moderate to very high amounts of astigmatism.
Toric Lens Implants | Astigmatism-Correcting IOLs
Toric lens implants are astigmatism-correcting IOLs designed with a specific shape that counterbalances the corneal curvature imperfection that creates astigmatism in the first place. Toric IOLs refocus light rays as they pass through the lens. The result is a near-perfect and long-lasting correction of astigmatism, along with a complete restoration of distance vision. This lens is a wonderful option for anyone over 50 who has pre-existing astigmatism.