Waterman's sunglass lens
View Patent ↗An improved ten-layer performance polarized lens for sunglasses. The lens design maximizes the benefit to watermen, giving them a combination of outer hydrophobic overcoat to protect the lens from seawater and smudging, multi-layer dielectric mirror which further reduces glare and overall light transmission, two layers of high-contrast blue-blocking amber or color-discriminating grey ophthalmic CR-39™ plastic or polycarbonate, sandwiching a polarizing layer. The foregoing layers are arranged to provide a balanced light transmission profile optimum for use on the water in which 100% of UV-A & B light is absorbed to at least 400 nm. An alternative embodiment is described in which a Rugate filter is incorporated in place of or in addition to the multi-layer dielectric mirror. The resulting watermens' dielectric-mirrored sunglass lens reduces both overall light transmission and ocular photochemical damage, and is available in either high-contrast blue-light blocking amber or grey coloration.
1. A sunglass lens, comprising:
a multilayer dielectric mirror for reducing glare and overall light transmission, said dielectric mirror comprising six thin film layers;
a first layer of ophthalmic plastic colorized with color discriminating grey tint;
a second layer of ophthalmic plastic colorized with said color discriminating grey tint;
a polarizing layer encapsulated between said first and second ophthalmic plastic layers;
whereby said layers are arranged to provide a balanced light transmission profile in which substantially 100% of UV-A & B light is blocked to at least 400 nm, and average blue light transmission of said lens is less than 0.4%.
2. The sunglass lens according to claim 1 , wherein said first and second layers are CR-39™ plastic.
3. The sunglass lens according to claim 1 , wherein said first and second layers are polycarbonate.
4. The sunglass lens according to claim 1 , wherein said polarizing filter layer is molecularly bonded between said first and second ophthalmic plastic layers to avoid haze and delamination.
5. A sunglass lens, comprising:
a first layer hydrophobic overcoat for protection from seawater and smudging;
a second layer dielectric mirror for reducing light transmission and glare, said dielectric mirror comprising six thin film layers;
a third layer color discriminating grey-tinted ophthalmic plastic material;
a fifth layer color discriminating grey-tinted ophthalmic plastic material;
a fourth polarizing layer molecularly bonded to said third and fifth plastic layers and sandwiched there between to avoid haze and delamination;
whereby said layers are arranged to provide a balanced light transmission profile optimum for use on the water in which at least 99.94% of UV-A & B light is blocked to at least 400 nm and average blue light transmission is 6.84%.
6. The sunglass lens according to claim 5 , wherein said third and fifth ophthalmic plastic layers are CR-39™ plastic.
7. The sunglass lens according to claim 5 , wherein said third and fifth ophthalmic layers are polycarbonate.
8. A sunglass lens, comprising:
a first layer hydrophobic overcoat for protection from seawater and smudging;
a second layer dielectric mirror for further reducing light transmission and enhancing UV obstruction;
a third layer color-discriminating grey-tinted ophthalmic CR-39™ plastic;
a fourth polarizing layer;
a fifth layer color-discriminating grey-tinted ophthalmic CR-39™ plastic;
whereby said layers are arranged to provide a balanced light transmission profile optimum for use on the water in which at least 99.94% of UV-A & B light is blocked to at least 400 nm and average blue light transmission is 6.84%.
9. The sunglass lens according to claim 8 , wherein said second layer dielectric mirror further comprises a multi-layered dielectric mirror.
10. The sunglass lens according to claim 9 , wherein said second layer multi-layered dielectric mirror further comprises at least six thin film layers vacuum deposited atop said third layer for further reducing light transmission and glare.
11. The sunglass lens according to claim 10 , wherein said fourth polarizing layer is molecularly bonded between said third and fifth CR-39™ lenses to avoid haze and delamination.