Online purchasing of eyeglasses has become much more popular in the past few years. Many people are coming in to our office are asking for their “PD.” The PD (inter-pupillary distance) is the distance measured from the center of one pupil to the center of the other pupil. This measurement is done in millimeters with a ruler, a device called a pupilometer, or by using your computer/phone camera.
This measurement has been somewhat trivialized by the online glasses industry in recent years. The PD is a measurement that is crucial to making glasses correctly. This measurement is even more critical with strong glasses prescriptions. Optometrists and ophthalmologists are the doctors that prescribe the correct prescription to be put in the lenses. Opticians (professionals that fit and make eyeglasses) have always been the professionals that measure the PD. This leaves consumers and doctors trying to figure out who is responsible for the PD measurement when glasses are ordered online.
The PD needs to be measured differently according to the type of lenses that are being put in the frame. A different PD measurement will be done for progressive lenses, reading glasses, or distance glasses.
As online glasses sites are becoming more popular, they are offering consumers easier online tools to measure their own PD. At our office, since we do not make or sell eyeglasses, we generally advise people to use online tools at home to measure their own PD. If the prescription is strong, or if bifocals are being ordered, we still recommend seeking the professional help of local opticians to measure the PD correctly.
Dr. Ivanoski is an Optometrist at Madison Medical Eye Care with offices in Mequon & Saukville, Wisconsin. He welcomes patients of all ages into his practice and accepts most insurance plans.
For more eye care information, call 262-241-1919 or visit www.MadisonMedicalEyeCare.com.