If you want to order eyeglasses online, it is very important to understand your prescription. The numbers on your eyeglass prescription relate to the shape of your eyes and strength of your vision. They can help you figure out whether you have nearsightedness, farsightedness or astigmatism and to what degree.
How to read the prescription written by doctors? Let's read it together.
This is the most common format
with clearly printed fields for OD, OS, SPH, CYL, AXIS and PD, Sphere (SPH) and Cylinder (CYL) always have a (+) or (-) sign.
PD can be written in different ways:
e.g. 63(Single PD), 32/31 (Dual PD), or 63/60 (Distance PD/Near PD).
Unlike typical Rx formats, with values going from left to right,
The vertical Rx values are listed top to bottom.
1) For multi-focal glasses, as well as reading and computer glasses, your Rx will include an ADD or NV value. This number always has a (+) sign.
2) The type of Rx glasses may be noted on a prescription, such as DV [Distance Vision/nearsightedness] and NV [Near Vision/reading].
The less common prism Rx refers to the amount of prismatic power needed to compensate for eye alignment issues. The prism Rxmust have two values: PRISM & BASE.BOmeansBase Out, BImeansBase In, BUmeansBase Up and BD (or BDn)meansBase Down.
There are many different ways that an eyeglasses prescription can be printed, but they will all have the same basic information.
OD = right eye
OS = left eye
Spherical power indicates the amount of lens strength, with positive values (+) indicating farsighted and negative values (-) indicating nearsighted.
The added lens power is for presbyopia and is an additional strength for your lens for reading or upclose work.
Numbers of corrections required for astigmatism. CYL or cylinder is the degree of how flat your eye is. Axis is the position, in degrees, corresponding to the degree of astigmatism
The interpupillary distance is the distance between the centers of the pupils of the eyes. How To Measure Your PD By Yourself?
Prism is the amount of prismatic power, measured in prism diopters. Base Direction indicates where the thickest edge of the prism will be.
