Coated glasses is the use of optical thin film and vacuum technology, surface coated with a layer of the lens material, to improve the ability to reflect light lens, serve to enhance or reduce the role of light through. There are two coated glasses: one is reflective filter chip: the lens surface gold, silver, zinc sulfide, etc. Coating can reflect visible light, infrared, and r-ray, the eyes play a protective role. The other is anti-reflective lens piece by: magnesium fluoride coating on the lens surface, silica, aluminum fluoride, zinc oxide, etc., can reduce the specular reflection, to improve the transmittance of the lens. Appearance of the United States to help photographers take pictures.
Coated glasses advantages: (1) a clear vision, reducing the specular reflection of light, an increase of light transmittance. (2) coated glasses can prevent the ultraviolet, infrared, X-ray damage to the eyes. Wear eye glasses coating fatigue, foreground screen staff for the vision can be protected. (3) coating the surface of the spectacle lens can reduce the reflected light, bright light to solve the difficult problem of camera glasses, an increase of beauty.
(4) coated glasses can withstand harsh environments, such as high temperature, rain, sea water immersion. (5) wear (dura mater), either inorganic material or organic material made of glasses, in daily use, due to dust or sand (silica) can cause friction wear lenses, the lens surface in the designated marks. Compared with glass, rigid organic materials is relatively low, more prone to scratches. Through the microscope, titanium dioxide we can observe scratches the surface of the lens is divided into two kinds, one is generated as gravel scratches, light and small, wearing glasses is not easy to detect; the other is generated by the larger grit scratches , deep and rough around, in the central region will affect the vision.
(6) can prevent "ghosting", glasses, optical glasses and the refractive power of the theory that makes the person wearing glasses, as the objects in the far point to form a clear image, can also be interpreted as the visual light deflected by the lens and the occurrence gathered on the retina, the formation of image point. However, due to the surface before and after refractive lens curvature different, and there is a certain amount of reflected light between them will produce internal reflection of light. Reflected light is far within the penalty area in the vicinity of the virtual image produced, barium titanate as in the retina that is generated near the point of virtual image. The virtual image point will affect the visual clarity and comfort. (7) can prevent "glare", like all optical systems, the eye is not perfect, as in the image on the retina is not a point, but a circle of confusion. Therefore, the feeling of two adjacent points is more or less by two parallel overlapping circle of confusion generated. As long as the distance between two points is large enough, the image on the retina will produce the feeling of two points, but if two points are too close, then the two circles will tend to blur and overlap, be mistaken for a point. Source: