Measuring your PD
Your pupillary distance (PD) is the distance between the centre of your pupils, measured in millimetres. Your PD is especially important for strong Prescriptions (over +/- 4.00 sph) to ensure the lens is positioned correctly.
There are many ways to measure your own PD. For iPhone users, the ‘EyeMeasure’ app provides all the measurements necessary for us to make your glasses, as well as being free and easy to use! Your PD can also be measured manually. Place any kind of ruler above your eyes and a measure the Distance between your pupils (the black spot in the middle of the coloured part of the eye). The average PD for males is 63, the average PD for females is 60, but it isn’t uncommon to go above or below those values.
If you can’t measure your PD, select ‘Don’t know/average’ and our lab team will use the average measurement for your glasses. If we need any Information about your PD, we will contact you.
If you dont provide us with a PD, we will use these generally accepted default measurements. For lenses, other than varifocals, the default PD measurements we will normally use will be as follows:
|Distance Glasses:||60 mm||63 mm|
|Reading Glasses:||58 mm||60 mm|
These default PD measurements may vary slightly depending on certain known factors and indicators regarding the frame (in particular, the frame size).
How do you measure OC height Varifocal for Glasses?
Ocular Centre Height refers to the vertical positioning of your pupils behind each of their respective lenses. This is measured in mm from the centre of each pupil to the lowermost section of the lens within the rim of a glasses frame.
If you want ‘varifocal’ lenses we may also need you to measure your Ocular Centre ‘Heights’. If we need this measurement we will contact you.
In other words, we use your PD and your OC height to horizontally and vertically align your pupils with the middle of each of your lenses.
Oh, and because your new glasses are a different shape, this measurement is entirely unique to how your specific glasses frame rests on your head – your OC changes from frame to a frame.