subject: How To Read Eye Prescription? [print this page] It is common for people to use eye prescription while buying glasses. However, most of them do not have a clear idea about it. Here are some tips about it, hoping they can help a lot in their daily lives.
Usually, prescription is the combination of a series of numbers and symbols. Such as, the figure about the right eyes and left eyes- the power, curve, PD, etc. Here are some typical terms about it.
Sphere is related to the degree of the problem. For example, it can tell how serious a specific eye is, and the number to be added or lessened. Usually, different eyes have different number.
Cylinder refers to the possibility and degree of astigmatism. The number in this item can tell how serious the astigmatism is. People with astigmatism have deformed eye balls. And the larger the number is, the more serious the problem will be. If the number is over -2.00, some special lenses are needed.
Axis is firmly related to, to which angle the lenses will be fixed on the frames. Astigmatism of different degree requires different angles, with a range of 1 to 180 degrees.
Add will appear on prescription for reading glasses or computer glasses. The number in this item can tell the degree of adding extra lenses.
PD is also a very commonly discussed item. It is the abbreviation of Pupil Distance- the distance between two pupils.
