Spin coating technique is used for making a thin coating on relatively flat substrates. The solution of material to be coated is deposited onto the substrate which is spun off at a high velocity in a range of 1000-8000 rpm and leaving a uniform layer.
Spin-coating technology makes the photochromic coating on the surface of lens, so color only changes on lenses surface, while in-mass technology make the whole lens change color.
Spin coat photochromic lenses work the way they do because the molecules that are responsible for the darkening of the lenses are activated by the ultraviolet radiation in sunlight. UV rays can penetrate clouds, which is why photochromic lenses are capable of darkening on cloudy days. Direct sunlight is not required for them to work.
They shield eyes from 100 percent of the harmful ultraviolet rays from the sun.
This mechanic is also used inside most windshield glasses in cars. Windshields are designed this way to help drivers see in sunny conditions. This also means that since the UV rays that enter a car are already filtered by the windshield, spin coat photochromic eyeglasses will not themselves darken.
Spin Coat Photochromic Lenses is available in blue block and non blue block.
Blue block Spin Coat Photochromic lenses help protect against harmful blue light both indoors and outdoors. Indoors, blue block spin coat photochromic lenses filter blue light from digital products. Outdoors, they reduce harmful UV light and blue light from sun light.
EMI layer: Anti-static
HMC layer: Anti-reflective
Super-Hydrophobic layer: Water-repell
Photochromic layer: UV protection
Monomer Photochromic Lens | Spin Coat Photochromic Lens | |||
Blue Block | Available | Available | ||
ANTI UV | 100% UV Protection | 100% UV Protection | ||
Index Available & Power Range | 1.56 | 1.56 | 1.60MR-8 | 1.67 |
sph -600~+600 | sph -600~+600 | sph -800~+600 | sph -200~-1000 | |
cyl -000~-200 | cyl -000~-200 | cyl -000~-200 | cyl -000~-200 | |
Coating | HMC: Anti Reflection | SHMC: Anti Reflection, Water Repellent, Anti Smudge | ||
Advantages and Disadvantages | Normal wastage, price is fair. | High wastage, price is higher. | ||
Color change fast; color fade slowly. | Color change fast; color fade fast. | |||
Color doesn’t change uniformly; Lens edge is darker, lens center lighter. | Color change uniformly; Lens edge and lens center have same color. | |||
High power lens is more darker than low power lens | Same color between high power and low power | |||
Lens edging is as easy as normal lens | Lens edging process should be more careful, because spin coating is easy to peel off. | |||
More durable | Short service life |