Once the fit is confirmed, your doctor is legally required to give you a digital or paper copy of your prescription. Key Prescription Details A standard contact lens prescription usually includes:
The specific manufacturer or lens type prescribed. do you need a prescription to buy contacts
Under federal law—specifically the —contact lenses are classified as medical devices. This applies even if you are buying "cosmetic" or "color" lenses that don't correct your vision. Why a Prescription is Required Once the fit is confirmed, your doctor is
The strength needed to correct your vision. Base Curve (BC): The back curvature of the lens. Diameter (DIA): The width of the lens. This applies even if you are buying "cosmetic"
Understand the specific numbers on your current prescription box.
Eyes vary in shape. An eye doctor must measure the base curve and diameter to ensure the lens doesn't scratch the cornea or cut off oxygen.