The next number on your prescription is the cylindrical correction or CYL. This concerns how much of an astigmatism you have. Astigmatism occurs when the cornea or lens of the eye is more curved ...

Based on the analysis of Holden, [6] this suggests that, on average, astigmatism of ≥1.50 D remains uncorrected among contact lens wearers worldwide. However, this undercorrection rate would be ...