How do I read and fill in my prescription (Rx) online?
Below are the prescription example chart:
· The top row (O.D.) is the information for your right eye.
· The second row (O.S.) is the information for your left eye.
SPH = SPHERE - The amount of long or short sightedness.
This value specifies the optical power of a lens in diopters. It always has a plus (+) or a minus (-) sign in front or above it. The lens power for the distance correction will be minus while the correction for near distance and reading will be plus power. There will always be a value for sphere, even if it is just zero (written as 0.00, Plano or P).
As above sample chart, the patient's right eye needs a power of -3.25 and left eye needs a power of -3.50. If the doctor put down “P” or “Plano” in this field, you can choose PLANO when ordering.
CYL = CYLINDER - This is the measurement for astigmatism. There is always a plus (+) or minus (-) sign & this will not shows in your prescription if you don’t have astigmatism.
As above sample chart, the patient's right eye has a CYCLINDER NUMBER -1.25, the left eye does not have a CYCLINDER NUMBER, the doctor may leave it blank or put down placeholder like "SPH(sphere)" or "DS" (diopters sphere , it means that you have sphere power only), in that case, you can leave this field blank when ordering.
AXIS - This appears if there is a value for cylinder, as it relates to the cylindrical lens and denotes a reference point that indicates the direction of the power of the cylindrical lens. It will be a number between 1 and 180. It may or may not be written with a degree 'o' symbol after the number. The doctor sometimes put down three digit number(060) or x+two digit number(x 60), both means the CYCLINDER NUMBER is 060 .
As you can see in the sample chart, the doctor put down a number "060" for the right eye since it has CYCLINDER NUMBER, and leaves it blank for the left eye, since the left eye does not have a CYCLINDER NUMBER. In that case, you can leave this field blank when ordering.
PRISM and BASE are usually left empty, as they are not seen in most prescriptions. Prism refers to a displacement of the image through the lens, and is used to treat eye muscle imbalances or other conditions that cause errors in eye orientation or fixation. Prism correction is measured in "prism diopters", and Base refers to the direction of displacement.
If there is no value for PRISM, you can leave this field blank when ordering.