Astigmatism is a type of glasses prescription required when your eye is shaped like a football, rather than a basketball. Most people (about 70%)  have significant astigmatism.

It can get a little confusing, as astigmatism occurs in the cornea (clear window on the front of your eye), and inside the natural lens of your eye.

The amount of astigmatism in your glasses is a combination of these two types of astigmatism. There are special diagnostic machines that can analyze the astigmatism in your eyes.

Astigmatism Diagnostic

Cataract surgery removes the cloudy lens of the eye, and replaces it with an intraocular lens implant (IOL).

What is a TORIC IOL?

It is possible to get a special IOL with an astigmatism correction incorporated into the optics of the implant.

These implants are called TORIC intraocular lens implants.

If you have significant astigmatism, a TORIC IOL will give you more clear distance vision without having to wear glasses.

Your surgeon will need to do special testing preoperatively to determine the amount and axis of your astigmatism.

If you decide to have a TORIC IOL, on the day of surgery small ink markings are made on the surface of the cornea to mark the axis of your astigmatism.

The TORIC IOL also has markings (four small dots in a line), which will need to line up with the markings your surgeon has placed on your cornea (purple marks).


Standard cataract surgery with a monofocal IOL does not correct for astigmatism.

If a monofocal IOL (as opposed to a TORIC IOL) is used for cataract surgery, your astigmatism would be corrected in your glasses after surgery by your optometrist.