Here is a typical contact lens prescription:
Eye Power(sphere) BC Dia Brand
OD (Right) -2.25 8.8 14.0 Acuvue
OS (Left) -3.00 8.8 14.0 Acuvue
Here are the definitions of the symbols used:
OD - Right Eye
OS - Left Eye
OU - Both Eyes
BC - Base Curve
Dia - Diameter
Toric (Astigmatism correcting) lenses will also contain two additional numbers:
Cyl - Cylinder and Axis
Bifocal contact lenses generally contain one additional number which is the
add power. A special field will be given for this number.
1. A contact lens prescription is not the same as an eyeglass prescription. In
addition to the lens power, your contact lens prescription contains several other
pieces of information related to the size of the lens.
2. Your prescription will also contain an expiration date. This is typically
two years from the date that the contact lenses were fitted.
3. BC values range from about 8.0 to 9.5. The doctor fits the lens with the
curvature most appropriate for your eye. Most lenses come in several different
BC values. If your prescription does not contain a BC value, this is likely because
your brand of lens only comes in one base curve.
4. BC values are a bit like clothes sizes - just because you are a BC 8.6 in
one brand doesn't mean you will be in another.
5. If you are in a toric lens your prescription will contain two additional
columns entitled cylinder and axis. These numbers related to the correction of