Sapphire single crystal features the following: a broad transmission wave band, high transmission, high strength, high hardness, high melting point, high heat conductivity, high heat impact quality factor, low scattering, low modulus of elasticity, low heat radiation, resistance against corrosion, high temperature, abrasion, jet fuels, the scouring and erosion by hailstones, rainwater, seawater, salt mist and sands, strong light irradiation. These characteristics enable them to work in adverse environment of high temperature and pressure. Therefore, it plays a role irreplaceable in serving as the optical protection windows of satellites, space technology and submarines. Most of the numerous merits are not found in resin lenses and ordinary glass lenses.
Sapphire has a fairly high hardness, which is second only to that of diamond and 7 times that of steel. This has addressed the weak impact resistance and excessive weight because of which traditional ordinary glass is castigated. Thanks to the high hardness, we can make it into ultra-thin lenses. Sapphire crystal glass has a body dislocation density of ≤2000 and an uncoated light transmittance of 85%. Through the excellent coating process of Sunphey, the one-sided and two-sided coated light transmittance can reach 92% and 98% or higher respectively so that the glass can not only tackle adverse scenarios, but also always maintain a clear field of vision.
The high hardness and strength of the sapphire spectacle lenses of Sunphey can effectively meet the requirements of spectacle lenses for resistance against impact and abrasion. Meanwhile, the refractivity of the sapphire spectacle lenses of Sunphey is higher than that of glass lenses so that their thickness is less under the same optometric readings, thus solving the excessive weight of the spectacles and the discomfort of wearing them. If used on myopic sunglasses of glass, the lenses can meet the requirements of general or highly myopic people for light wearing.