Eyes with Astigmatism have corneas that are shaped more like an rugby ball than like a soccer ball. This causes the light rays to bend differently across the corneal surface. As a result, the lightrays do not intersect in one sharp focus point but rather form several focus points, either before or behind the retina. Images are defocused and distorted.
Irregular astigmatism occurse in case with remarkable distortion of the cornea like keratoconus and corneal ectasia
Astigmatism correction makes all the rays of light focus at the same distance so that they all fall correctly on the retina.
Astigmatism can occur alone as the sole optical error, or may occur together with either myopia or hyperopia. It can be corrected by glasses, contact lenses (hard or soft toric), and lasik vision correction. When natural lens removal is planned (like when removing the opaque lens or cataract), the newly introduced toric intraocular lenses can be implanted to correct the astigmatism together with lens power needed.
