Is there a simple formula to convert a glasses prescription to a contact lens prescription? Why are glasses and contact lens prescriptions often different?

CYL - Cylinder (usually a number between -0.5 to -2.25). AX - Axis ... A contact lens prescription is not the same as an eyeglass prescription. In ... What is the diameter of contact lenses? The diameter of a contact lens ... What does 'cylinder' mean? Cylinder (CYL) is always a minus number, such as ... Sep 6, 2015 ... What does each prescription figure mean? Power/Sphere (PWR/SPH): This figure states whether you are long or short-sighted and how poor your ... » BRAND = The brand name given to the contact lens - for example "Soflens" or "Acuvue". For astigmatic patients, there is also the following parameters: » CYL ( ... Jan 17, 2024 ... Decoding your eyeglass prescription? Understand what Sphere, Cylinder, and Axis mean for your vision correction. CYL means cylinder. This measurement is only recorded on your prescription if you have astigmatism. Astigmatism is any abnormality in the curvature of the ... Mar 25, 2025 ... What Does Power Mean for Contacts? ... PWR means refractive power, but sometimes it can be abbreviated as SPH (sphere). This is the amount of ... Apr 18, 2023 ... What does “sphere (SPH)” mean on my prescription? The sphere column ... A contact lens prescription includes measurements specific to the size and ... Oct 26, 2022 ... So what do each of these contact lens prescription figures mean? · Base curve (BC) · Diameter (DIA) · Power/Sphere (PWR/SPH). Sep 26, 2023 ... Knowing the proper axis is crucial for ensuring your lenses are correctly aligned. Why Is Your Contact Lens Prescription Different? If you ...