Astigmatism is a condition where the optical
power of the eye varies depending on the
angle of light passing through it.
Astigmatism produces blurred vision at all
It is usually due to the shape of the cornea
(the front surface of the eye).If the
curvature of the cornea is not the same in
all directions (like the side of an
Australian football) it will bend the light
passing through it by different amounts
depending on the direction of the light,
Astigmatism is a focusing error which causes
asymmetric blur. Some directions in an image
are more out of focus than others.
be contrasted with short-sightedness
(myopia) where all directions are uniformly