Help and frequently asked questions

What is astigmatism and how can it be corrected?


People with astigmatism have an unevenly curved cornea (the clear covering at the front of the eye) or an unevenly curved lens inside their eye, shaped more like a rugby ball than a football. Imagine a rugby ball sliced in half, lengthways.

The cut surface is an oval shape, and imagine you are looking at it from its pointed end - the sides curve up steeply. Now imagine you're looking at it from halfway between the two pointed ends - the sides curve much less steeply. This is an exaggerated version of the shape of an astigmatic cornea.

It is corrected by spectacles with a cylinder shape built into the lenses at a certain angle. Contact lenses can also correct astigmatism - mild astigmatism can be corrected by an ordinary gas-permeable lens. Those who prefer a soft lens or have higher amounts of astigmatism can use specially designed, 'toric' soft lenses.