Views:720 Author:Site Editor Publish Time: 2020-07-17 Origin:Site
A common problem with sunglasses is that they are prone to glare. The role of the anti-reflective coating is to reduce the reflection of light by the lens. Like the anti-scratch protection layer, the anti-reflective coating is a very solid and thin film on the lens. Do you know the benefits of anti-reflective sunglasses?
AR coating is especially beneficial when used on high-index lenses, which reflect more light than regular plastic lenses. Generally, the higher the index of refraction of the lens material, the more light that will be reflected from the surface of the lenses.
For many people, the night driving glasses with an anti-reflective coating can help when driving at night. People wearing normal glasses experience the halo effect around headlights and street lamps when driving in the dark. The anti-reflective coating eliminates this effect and can make night driving less of a distraction.
The anti-reflective glasses can also be beneficial if you spend a great deal of time on the computer. Working on a computer for an extended period of time can lead to eye strain, as your eye muscles struggle to view specific areas of the monitor and battle the glare. Typical symptoms of eyestrain while working on the computer include blurry vision, dry eyes, and irritation. The anti-reflective coating can decrease eyestrain and make it possible to work on the computer for longer periods of time without difficulty. Eyestrain can also happen to people who do not work on computers on a regular basis. Spending a great deal of time in a dimly lit room, for example, can lead to eyestrain. If you experience eyestrain, no matter the reason, the anti-reflective eyeglasses may be able to help.
Anti-reflective sunglasses also improves your appearance, particularly when taking photographs. With glasses that do not have this coating, pictures often show reflected light and you can't see your eyes. With the coating, your eyes are more easily seen.
Applying anti-reflective coating to eyeglass lenses is a highly technical process involving vacuum deposition technology.
The first step in the AR coating process is to meticulously clean the lenses and inspect them for visible and microscopic surface defects. Even a tiny smudge, piece of lint or hairline scratch on a lens during the coating process can cause a defective AR coating.Typically, a production line includes multiple washing and rinsing baths, including ultrasonic cleaning to remove any traces of surface contaminants. This is followed by air drying and heating of the lenses in special ovens to further remove unwanted moisture and gases from the lens surface.
The lenses are then loaded into special metal racks with spring-loaded openings so the lenses are held securely but with virtually all lens surfaces exposed for the coating application. The racks are then loaded into the coating chamber. The door of the chamber is sealed, and the air is pumped out of the chamber to create a vacuum. While the lens racks are rotating in the coating chamber, a power source within the machine focuses a beam of electrons onto a small crucible that contains a series of metal oxides in separate compartments. When the coating materials are bombarded by electrons, they vaporize within the coating chamber and adhere to the surfaces of the lenses — creating a uniform, microscopically thin optical layer on the lens.
Each AR coating manufacturer has its own proprietary formula, but generally all anti-reflective coatings consist of multiple microscopic layers of metallic oxides of alternating high and low index of refraction. Depending on the AR coating formula, most lenses with anti-reflective coating have a very faint residual color, usually green or blue, that is characteristic of that particular brand of coating. Anti-reflective coatings are incredibly thin. The entire multilayer AR coating stack generally is only about 0.2 to 0.3 microns thick, or about 0.02 percent (two one-hundredths of 1 percent) of the thickness of a standard eyeglass lens.
In a word, the anti-reflective coating can help improve your vision and also reduce the glare from your lenses. This coating will remove reflections, thus allowing more light to pass through the lens, which will optimize your sight, especially at night. This is why I recommend anti reflective coating glasses to everyone.