When the front surface of the eye (the cornea) is spherical in shape–like a basketball–light passes through it and focuses to a clear single point in the back of the eye, giving clear vision. However, when the curve of the cornea is different horizontally than it is vertically, like a football–light that passes into the eye is scattered into multiple points. This scattering of light gives blurred vision and is called astigmatism. Cataract is a separate problem where the natural lens inside of the eye starts to cloud and become less transparent. You can learn more about cataracts here.
How is astigmatism treated?
Astigmatism can be treated in many ways – including eyeglasses, contact lenses, LASIK, AK (Astigmatic Keratotomy), and LRI (Limbal Relaxing Incision). However, if you have astigmatism and cataract, there is now an implantable intraocular lens called a Toric IOL that makes it possible to treat both cataract and astigmatism at the same time.
What is the difference between a Toric IOL and a standard IOL?Cataract surgery is essentially the same regardless of the lens used at the time of the surgery. Using a Toric IOL does require a small additional step by the surgeon before and during the surgery. Before the surgery, the doctor will use a special marker to make a mark at the surgery site to aid in positioning the lens correctly during the surgery. Once the lens has been implanted, it will be rotated in the eye by the surgeon to ensure correct positioning. It is this precise positioning that allows a Toric IOL to compensate for astigmatism after surgery and give sharp distance vision, often even without distance glasses.
There are risks to any procedure done anywhere on your body, including your eyes. Use of a Toric IOL during cataract surgery does not negate nor add to this risk. A detailed discussion of risks, benefits, and alternatives to surgery should be had with your surgeon before any procedure. Surgical results cannot be guaranteed.