Eyeglass Lens Measurements

• Pupillary Distance, Pupil Distance or PD

• If you're ordering lenses for a new frame, you will need to provide your Distance MONO PD (monocular pupil distance). Have your doctor include this on your prescription or have a local eye care professional measure this for you. A MONO PD measurement only takes a minute and there is usually no charge for this service.
• If the frames you're sending us for replacement lenses have your existing prescription lenses, they have been working well and they are the same lens type as the lenses you're ordering (progressive, bifocal, trifocal or single vision) then dotting your pupil center is not necessary. (We will fit the new lenses with the same fitting information as your old lenses).

Fitting Height or Segment Height

• Dot the pupil center on each lens with a permanent marker. This can be done in front of a mirror or by having another person do it for you. Be sure to keep your head still while passing the pen from one eye to the other and keep the dot small. Dotting the lenses is used for the vertical placement of a progressive, bifocal, trifocal and some single vision lenses and is not considered an accurate PD measurement.
• If your frames do not have any lenses in them at all (prescription lenses, demonstration or dummy lenses) you can place clear tape over the right and left lens opening of the frame as a surface to draw the dots.

If you need any further assistance with this procedure please email or call Eyeglass Lens Direct.

Glasses lens replacement has never been easer.