The rays appear to spread as a line in various directions and vision can be blurry, distorted, or shadowy at distance or near.
Correction for astigmatism is given in the form of a cylinder A cylindrical lens bends light along only one axis as only one of its axes is curved. Astigmatism is corrected by introducing a cylindrical lens of opposite refractive properties.
The axis of the cylinder follows the longest axis of the eye. The power of the cylinder is perpendicular to the axis.
Example: -1.00 x 180. Patients may have a combination of astigmatism and spherical refractive error. In that case, the physician may correct the problem by combining a spherical lens with a cylindrical lens placed along the appropriate axis. Example: -2.00 / -1.00 x 180
With LASIK refractive surgery, the refractive error of astigmatism can be eliminated and vision restored by changing the cornea shape which is irregular or not smooth, into a cornea which is regular or smooth.