1.56 refractive index semi-finished lens combines three advanced technologies in one solution: photochromic adaptability and progressive multifocal design. The lens blank begins as a precision-cast “puck” containing light-sensitive molecules that automatically darken when exposed to UV/visible light (activating outdoors while remaining clear indoors), while offering built-in 100% UV protection. As a semi-finished product, it allows optical labs to customize the front surface with freeform progressive designs, creating seamless distance-to-near vision corridors tailored to individual prescriptions.
| SF 1.56 PHOTOCHROMIC PROGRESSIVE HMC 75/12&14MM | ||||||||
| Material Refractive Index=1.56 Tooling Index=1.530 | ||||||||
| DIA (mm) | Nominal Curve |
Front Radius(mm) |
Front Curve |
Rear Curve |
C.T (mm) |
E.T (mm) |
Front Sag Ring 50mm |
Rx Range |
| 75 | 2.00 | 378.57 | 1.40 | 5.00 | 9.00 | 15.00 | 0.53 | -3.25 to -6.00 |
| 75 | 4.00 | 155.88 | 3.40 | 5.00 | 7.00 | 8.65 | 2.02 | -1.00 to -3.00 |
| 75 | 6.00 | 92.98 | 5.70 | 5.00 | 9.20 | 7.50 | 3.42 | +0.25 to +3.00 |
