Segment height
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Segment height is a measurement needed when ordering progressive or bifocal glasses online. It refers to the vertical distance from the bottom of the lenses to the pupil. Knowing the segment height ensures the reading portion of progressive lenses is placed correctly. If the current frames are unavailable, measure similar frames owned to get the height and width for fitting purposes. The document then provides steps to accurately measure segment height with a ruler by aligning it with the bottom of the lens while facing a mirror.
Segment height
- 1. O P T O M . A S K A R P K Segment Height Measurement
- 2. What is it? And why is it relavant when ordering progressive or bifocal glasses?
- 3. Segment Height, can also be known as Seg Height or SH and it is a value that may or maynot be included in your progressive or bifocal prescription
- 4. When you order progressive or bifocal glasses online the segment height is a very helpful measurement and while not all doctors will provide this measurement even when ordering glasses in person this measurement is very specific to the actual frame and the person wearing them
- 5. This is the distance (the vertical measurement) from the bottom of the lenses to where your eyes (pupils) are. You need this measurement so that when you order your progressives the optican will know where to put the reading portion of your glasses Segment height does not apply to Single Vision lenses What can you do if you don't have the glasses you are about to order on hand?
- 6. Measure the glasses that you currently own and try to find glasses very similar to those The measurement to look for in this case is the height and for fitting purposes the width of the frame
- 8. How to Measure Your Segment Height 1. Use a ruler that has millimeter measurements. You can also use a ruler with centimeter measurements and simply times the result by 10 to get your millimeter measurement. 2. Put the glasses on your face and adjust them so that they sit comfortably. 3. Stand about 8 inches (20 cm) away from a well lit mirror with your face parallel and square to the mirror.
- 9. 4. Align the ruler's zero (0) measurement to the lowest point at the bottom of your 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 above). 5. Stare straight ahead and read the millimeter line that lines with the center of your pupil. This is your segment height measurement for these frames. 6. 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 lens until you note your measurement. Ask a friend to help if you are having trouble.
- 10. Thank You