Once your eye examination is done and all the required tests are done then the optometrist will hand you a copy of the prescription. This will contain the exact measurements of the prescription lenses that you will require in order to have the most comfortable and clear vision.
Sphere:A+ in the box indicates that you are long sighted and it means you will have difficulty seeing things close to you. A- will show you that it is difficult to see things that are far away without glasses. The number can be very small but higher the number the stronger will be your lenses needed. This will definitely influence your selection of frames. The lens curve will be greater if the prescription is higher.
Cylinder:The amount of astigmatism is caused due to an irregularly shaped cornea. If the number is low such as 0.25 then it will mean your eyes are round but not quite. A higher number will indicate that your eyes are oval shaped.
AXIS:The astigmatism direction is usually measured in degrees. The number helps to know the exact angle for positioning your lenses in the frame.
PRISM:This generally indicates that the eyes are not working properly. If there is any muscle imbalance between your eyes prism lenses that will give you the correction you require and assist preventing headaches and double vision.
BASE:Generally, the base tells the where to put the prism in the glasses.
ADD:If you are aged above 45 then your prescription night have this word. If so happens then this is going to be your reading addition that is related to the additional amount correction which is required for focusing at close distances. If a measurement is shown then it means that you will have different prescription for reading and distance. Varifocal or bifocal lenses may be required.
PD:Your pupillary distance is essential when creating lens that will match your prescription because you require the optical centre of each lens that will align with your pupils. Do not try to guess your own PD. The average PD is 62mm and most people fall within the range of 54mm – 74mm. If you are going for bifocal or progressive lenses then you must definitely get your PD prior to ordering.
Your prescription is the most essential element when you are making your purchase online. This will help each optical store to custom make each pair of glasses. So, go ahead and read your prescription before you fill out any form online for any optical store. Now that you are aware of the details of a prescription you can go ahead and read your prescription.