Astigmatism is a condition which occurs as a result of irregularities in the curvature of the cornea, which is not completely spherical. This means that light is focussed at different distances from the retina and leads to distortions in the perception of images.

Refractive surgery is recommended for patients over 20 years of age with myopia, hyperopia or a combination of the two within the range of 1 to 10 diopters either positive or negative.