Segment Height, also commonly referred to as Seg Height, is the vertical measurement in millimeters from the bottom of the lens in your frames, to the beginning of the progressive addition on a progressive lens, or the top line of a lined bifocal.
At Lensabl (and most online glasses/lenses retailers), we request your Seg Height measurements to ensure that your lenses are crafted exactly right for you.
There are two options explained below that will guide you on how to determine your measurements.
How To Measure & Submit Your Seg Height
Option 1 – Get A Professional To Do It
If you have easy access to a vision care professional who can mark your Seg Height on the lenses (typically with a Sharpie), we can take and use those measurements!
Option 2 – Selfie time! Send Us A Photo Using Your Camera, Face, and Card
When providing a photo, it is very important that the directions are followed carefully, so that we can take an accurate measurement. We use a credit card as the base measurement, so the card in the photo must be the same size.
The card should be held by two fingers — placed horizontally alongside your frames. Please note this is the same photo as the PD photo, but with the glasses on your face.
You must be looking directly forward at the camera lens — not angled in any other direction. Please wear the frames you are sending to our lab for this photo.