You can use this simulation to make vertical measurements on eyewear. In this example you might want to check the seg height.
Notice something different about this simulation. It has a dotted white line on the frame - at the bottom of the lens. Why is that?
For vertical measurements of mounted lenses, you have to account for the bottom of the groove in the frame. In the simulation you can't look directly at the groove, so the white line shows you where the bottom is. You can measure the seg height from that line.
Users can compare their measurements against the prescription shown.
Computer users: click and drag with your mouse.
iPad users: touch and drag with a stylus or with your hand.