How to Read an Eyeglasses Prescription What is the “cylinder (CYL)” number on my prescription? The cylinder number is how much astigmatism you have, if any This is when part of the cornea has a different curve Normally, an eye is shaped like a basketball—rotated any direction, the curve stays the same
What Does Cylinder (CYL) and Axis Mean in an Eye Prescription? When it comes to prescriptions, the cylinder (CYL) and axis values are particularly confusing for many people, especially when ordering contact lenses online Understanding these values helps you grasp exactly what’s happening with your vision correction
What is Cylinder (CYL) in Eye Prescriptions: A Complete Guide CYL stands for "Cylinder," and it is a measurement used in eye prescriptions to correct irregularities in the shape of your cornea or lens Unlike the SPH, which measures your overall nearsightedness or farsightedness, CYL targets astigmatism—an eye condition causing blurry or distorted vision
CYL Definition Meaning - Merriam-Webster “Cyl ” Merriam-Webster com Dictionary, Merriam-Webster, https: www merriam-webster com dictionary cyl Accessed 18 Nov 2025
What is CYL on eye prescription? - Banton Frameworks What does CYL mean on an eye prescription? CYL stands for Cylinder and refers to the dioptric strength required to correct astigmat i sm in either or both of your eyes
Prescription Lenses Eyeglasses Guide: What Does the CYL Number Mean? The CYL number in your prescription indicates the degree of astigmatism—the larger the number, the more significant the correction needed The CYL value is typically paired with an AXIS measurement (0–180 degrees), which tells the optician where the astigmatism occurs