The image shown on the right is a typical prescription found on a box of contact lenses. The most important values for ordering correctly are the Power and Base Curve as most contact lenses come in only one diameter.
POWER (PWR, SPH or D) is the strength of the vision correction and can be either plus or minus power. Plus and Minus powers are not interchangeable and great care must be taken when ordering. ORDERING PLUS OR MINUS POWERS INCORRECTLY IS THE NUMBER ONE MISTAKE. If you are nearsighted (can see near but not far objects clearly) order minus powers, if you are farsighted (can see distant but not close objects clearly) please order plus powers. Power is sometimes called Sphere (Sph) and is measured in Diopters (D). If you are unsure what to order please do not guess, please call us at (800) 536-7327.
BASE CURVE (BC) has to do with the shape of your eye and almost everyone has the same BC for both eyes. Many contact lenses come in only one base curve, many others in only two base curves, some come in multiple base curves so care must be taken when ordering. If your box or prescription says MEDIAN instead of a number for base curve and unless we have the word "Median" as a choice "Median" is usually BC 8.5, 8.6 or 8.7. If you are not sure and the contact your are ordering is available in more than one BC, please do not guess, please call your doctor or please call us for help.
DIAMETER (Dia or Diam) is the size of the lens in millimeters. Common diameters are 13.8, 14.0, 14.2, 14.4; more complicated soft contact lenses can be other sizes as well. Many disposable contact lenses are available in only one diameter; if you see only one choice for diameter you may confidently select that diameter.
TORIC contact prescriptions have two additional parameters; Cylinder (Cyl) and Axis (Ax). Cylinder is always a negative decimal (ie. -0.75) and Axis is usually expressed in increments of 10 from 10 to 180 (010 is 10).
MULTIFOCAL (bifocal) lenses can include a numeric "Add Power" (ie, +2.00) for magnification or simply "Low" or "High" power magnification and often a choice of D (dominant eye) or N (nondominant eye) option.
A quantity of one is usually one box of contact lenses, most contact lenses are packed in a box of six lenses also called a 6 pack. Vial lenses come as a single lens or in boxes of four lenses. Daily wear lenses are packed in boxes of 10, 30 or 90 lenses. In every case when you order a quantity of one you are ordering one vial or box of contact lenses.
All contact lenses are boxed in the IDENTICAL prescription. If you wear a different prescription in each eye you will need to order at least one box for each eye.
One 6 pack of two week disposable lenses is enough for a three month supply for ONE eye. Please order two boxes for a three month supply, four boxes for a six month supply and eight boxes for a one year supply.
One 6 pack of a monthly disposable lenses is enough for a six month supply for ONE eye. Please order two boxes for a six month supply, four boxes for a one year supply.
On your written prescription you may see:
OD: Right Eye
OS: Left Eye
OU: Both Eyes
Many lenses have similar names such as Frequency 55. This contact lens is available as Frequency 55, Frequency 55 Multifocal, Frequency 55 Toric and Frequency 55 Toric XR. If the numerical prescription choices on our product pages do not match your prescription it is likely are you are trying to order the wrong contact lens. Please give us a call at (800) 536-7327 for assistance.