Flat Top 1.56 Photochromic Gray Cr39 Eyeglass Lenses AR Coating

1) The most popular fused bifocal today has a D-shaped near segment rotated 90 degrees so that the flat part of the "D" is facing up. For this reason, D-seg bifocals also are called "flat-top" (FT) or "straight-top" (ST) bifocals.

2) This is a D segment bifocal lens. It has the benefit that the optical centre of the near vision part of the lens i.e. the part of the reading area which gives the very best vision, is situated at the top of the reading portion. Also the widest part of the reading area is just below the dividing line, and is the part of the lens the wearer would use.

1. Fast speed of changing, from white to dark and vice versa.

2. Perfectly clear indoors and at night, adapting spontaneously to varying light conditions.

3. Very deep color after change, the deepest color can be up to 75~85%.

4. Excellent color consistency before and after change.

When eye safety is a concern, polycarbonate lenses usually are the best choice for your eyeglass.

Both polycarbonate and Trivex lenses are thinner and lighter than regular plastic lenses. They also offer 100 percent protection from the sun's harmful UV light and are up to 10 times more impact-resistant than plastic or glass lenses.