How to Read Your Colored Contact Lens Prescription
You pick up your prescription from the eye doctor and it looks like someone spilled alphabet soup on a page. OD, OS, BC, DIA, PWR, CYL, AXIS. It might as well be in code. It basically is.
Here’s what every number means so you can order colored contacts confidently.
OD and OS
OD is your right eye. OS is your left eye. Simple once you know it. Your prescription will have one set of numbers for each.
PWR / SPH: Your Vision Power
This is your prescription strength. A minus sign means nearsighted. A plus sign means farsighted. Yilala lenses come in plano (0.00) for cosmetic use and -0.50 to -4.50 for vision correction. If your PWR is -4.75 or stronger, our prescription range does not cover it. You’ll need a higher power lens from a different source.
BC: Base Curve
This is the curvature of the lens. Yilala lenses use 8.6mm, which fits the majority of eyes. If your prescription specifies a different BC, your lenses may not fit as comfortably. The BC must match or come very close. A 0.1mm difference is usually fine. A 0.4mm difference will cause noticeable fit issues.
DIA: Diameter
Yilala lenses are 14.5mm. Standard prescription lenses are typically 14.0-14.2mm. The extra 0.3-0.5mm on our Berry Series and other lenses creates the eye enlargement effect. It will not cause fit problems for most wearers.
Your prescription is valid for one year in the US. After that, you need a new exam. Do not use an expired prescription. Your eyes change, and an old prescription can mean the wrong power, the wrong fit, or both.
Order prescription colored contacts with your current valid prescription.