Effect of astigmatism and spherical equivalent correction on contrast sensitivity

Binocular astigmatism defocus decreases CS depending on the degree of astigmatism power; correction of this will improve patent's quality of vision. Although high astigmatism refractive error (more than 2.00 DC) that is fully corrected by cylindrical spectacle lenses doesn't increase the CS to the maximum value, especially at higher spatial frequencies (12 and 18). Also SE refractive error effects on improving CS in low astigmatism power (less than 2.00 DC), especially at lower spatial frequencies.