When selecting a frame for progressives, keep this in mind:
Segment Height Accuracy
Make sure frame is sitting on your face properly. 3 point touch right ear left ear and nose bridge. Adjust frame to ensure proper sitting.
Follow the instructions below to measure your own Segment Height at home.
Put the glasses on your face and adjust them so that they sit comfortably.
Stand about 8 inches (20 cm) away from a well lit mirror with your face parallel and square to the mirror.
Align the millimeter ruler’s zero (0) measurement using a to the lowest point at the bottom of your left lens, keeping it exactly vertical.
Make sure you are measuring from the
bottom of the clear lens, not the bottom of the frame (see graphic).
Using a plastic ruler, this OC measurement would be approximately 29mm from the centre of his pupil to the bottom of his lens.
Stare straight ahead and read the millimeter mark inline with the center of your pupil. This is your segment height measurement for these frames.
(Quick tip: you can easily measure it yourself. See below for a diagram on how to dot the lenses. Use a wet or dry erase sharpie. Do not use permanent marker so you can repeat process a few times. Then just measure the dotted lenses to the bottom of the lenses. When you send them back do not leave any markings on lenses. Write down your measurement with a pencil and paper.
Repeat these steps at least 3 to 5 times to get an accurate and consistent measurement. Make sure your head and the ruler do not move after lining up the zero (0) measurement with the bottom of your left lens until you note your measurement. Ask a friend to help if you are having trouble.