SEG HEIGHT MEASURE
For measuring the height of bifocal segments. Millimeter graduations are imprinted on both sides for quick and accurate measurements up to 40mm.
Measure seg heights from the lowest point of the eyeglass lens. Use the same starting points as when measuring MRP heights. Segs should be positioned roughly one to three millimeters below the base of the patient's pupils. Bifocals should be set a bit lower, on average, and trifocals (top of the intermediate) just a bit higher than average.
The correct placement of segment heights tends to be somewhat of an art. If not placed correctly and evenly the patient may see a line or a prism effect.
Sturdy yet flexible heavy duty clear plastic segment height measure
Pack of 2