Power Parameter On Your Prescription

Power is a number from -20.00 to +20.00 following the words "Power" or "Sph" on your prescription form. Please be careful selecting the right "+" or "-" sign for the Power parameter. If you are near-sighted, you are probably wearing the "-" sign lenses.  If you are far-sighted, your are wearing the "+" sign lenses.  If your prescription was written as a string of numbers (e.g., "-3.00 -1.75 @ 180" for toric lenses, or "-2.00,high" for multi-focal), the first number in the string would usually represent the Power.