Waterman's sunglass lens
View Patent ↗An improved ten-layer performance polarized lens for sunglasses. The lens design maximizes visual acuity while minimizing blue-light transmission using a multi-layer dielectric mirror to reduces glare and overall light transmission, two layers of high-contrast blue-blocking amber CR-39 plastic or polycarbonate, sandwiching a polarizing layer. An outer hydrophobic overcoat is also provided to protect against haze, delamination, and smudging, 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. The resulting dielectric-mirrored sunglass lens reduces both overall light transmission and ocular photochemical damage.
1. A sunglass lens, comprising:
a first layer of opthalmic plastic colorized with high-contrast blue-blocking amber-tint;
a second layer of opthalmic plastic colorized with said high-contrast blue-blocking amber-tint;
a polarizing layer encapsulated between said first and second opthalmic plastic layers;
a multilayer dielectric mirror consisting of six thin film layers vacuum deposited atop the first layer of opthalmic plastic for further reducing overall light transmission and glare; 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 multi-layered dielectric mirror further comprises six thin film layers vacuum deposited atop said first layer of plastic for further reducing light transmission and glare.
5. The sunglass lens according to claim 4 , wherein said multi-layered dielectric mirror further comprises a thickness of between 2–3 nm.
6. The sunglass lens according to claim 4 , wherein said multi-layered dielectric mirror further comprises six alternating layers of TiO 2 and SiO 2 .
7. The sunglass lens according to claim 6 , wherein said TiO 2 has a high refractive index of approximately 2.35 and said SiO 2 has a low refractive index of about 1.45.
8. The sunglass lens according to claim 1 , wherein said polarizing filter layer is molecularly bonded between said first and second opthalmic plastic layers to avoid haze and delamination.
9. The sunglass lens according to claim 1 , wherein said first layer of opthalmic plastic and second layer of opthalmic plastic are both colorized with medium amber-tint.
10. A sunglass lens, comprising:
a first layer hydrophobic overcoat for protection.
a second layer dielectric mirror for reducing light transmission and glare, said dielectric mirror consisting of six thin film dielectric layers;
a third layer blue-blocking amber-tinted opthalmic plastic material;
a fifth layer blue-blocking amber-tintedopthalmic 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 substantially 100% of UV-A & B light is blocked and at least 99% of blue light is blocked at up to 490 nm and average blue light transmission of said lens is less than 0.4%.
11. The sunglass lens according to claim 10 , wherein said third and fifth layers are CR-39™ plastic.
12. The sunglass lens according to claim 10 , wherein said third and fifth layers are polycarbonate.
13. The sunglass lens according to claim 12 , wherein said multi-layered dielectric mirror further comprises a thickness of between 2–3 nm.
14. The sunglass lens according to claim 13 , wherein said multi-layered dielectric mirror further comprises six alternating layers of TiO 2 and SiO 2 .
15. The sunglass lens according to claim 14 , wherein said TiO 2 has a high refractive index of approximately 2.35 and said SiO 2 has a low refractive index of about 1.45.