Figure 1. Vision with astigmatism.
Astigmatism is where you have an asymmetric curvature of the cornea or lens of the eye which are normally curved equally in all directions. This causes distortion of light as it focusses onto the retina at the back of your eye preventing a sharp picture from forming (Figure 1). When you have cataract surgery there is an opportunity to treat the astigmatism. If the curvature problem is of the lens, it is corrected by removal and replacement with a non-astigmatic intraocular lens (IOL) that is implanted during cataract surgery. If it is of the cornea, either the cornea is relaxed with an incision or a special IOL that counteracts the astigmatism is implanted. Your astigmatism may come with other refractive errors like long or short sightedness that also need to be addressed during the surgery.
It is worth treating astigmatism surgically if you wish to become either free of spectacles for distance, or only need thin spectacles for distance. Most cataract surgery does not treat astigmatism and you are left with blurry vision or areas of distorted vision, eyestrain, headaches, squinting to try to see clearly, or eye discomfort; unless you wear spectacles. You can still have an IOL implanted on top of the original to correct it if you want to see well without glasses (Figure 2). If you have these symptoms you should book an appointment at Edgbaston Eye Consultants to see one of our consultants, who will give you a complete eye examination, determine what is causing your symptoms and offer a suitable treatment.
Figure 2. Intraocular lens implant to treat astigmatism after standard cataract surgery.