The knowledge of Photochromic lens 1. The definition of photochromic lens ①Photochromic lenses, often called transitions or reactolights, darken to a sunglasses tint when exposed to sunlight, or U/V ultraviolet, and return to a clear state when indoors, away from U/V light. ②Photochromic lenses are made of many lens materials including plastic, glass or polycarbonate. They are typically used as sunglasses that conveniently switch from a clear lens indoors, to a sunglasses depth tint when outdoors, and vice versa. ③Brown / Photo Grey Photochromic Lens For Outdoor Activities 1.56 Hard Multi Coated 2. Outstanding Color Performance ① Fast speed of changing, from white to dark and vice versa. ②Perfectly clear indoors and at night, adapting spontaneously to varying light conditions. ③Very deep color after change, the deepest color can be up to 75~85%. ④Excellent color consistency before and after change. 3. UV Protection Perfect blockage of harmful solar rays and 100% UVA & UVB. 4. Durability of Color Change ①Photochromic molecules are equally bedded in lens material, and are activated year by year, which ensure durable and consistent color change. ②You might think all of this would take quite a bit of time, but photochromic lenses respond remarkably quickly. About half the darkening happens within the first minute and they're cutting out about 80% of sunlight within 15 minutes. ③Imagine lots of molecules suddenly darkening inside a clear lens. It's a bit like closing the blinds in front of your window on a sunny day: as the slats turn, they progressively block out more and more light.5.What is the difference between HC, HMC and SHC？
| Hard coating | AR coating/Hard multi coating | Super hydrophobic coating |
| makes the uncoated lens hard and increases the abrasion resistance | increases the transmittance of the lens and reduces surface reflections | makes the lens waterproof, antistatic, anti slip and oil resistance |
| 1.56 photochromic semi-finished optical lens | |
| Model: | 1.56 optical lens |
| Place of Origin: | Jiangsu, China |
| Brand: | SETO |
| Lenses Material: | Resin |
| Bending | 50B/200B/400B/600B/800B |
| Function | photochromic & semi-finished |
| Lenses Color | Clear |
| Refractive Index: | 1.56 |
| Diameter: | 75/70/65 |
| Abbe Value: | 39 |
| Specific Gravity: | 1.17 |
| Transmittance: | >97% |
| Coating Choice: | UC/HC/HMC |
| Coating color | Green |