Anti-Reflective (AR) or Anti-Reflection coatings are optical coatings applied to the surface of lenses and other optical devices to reduce reflection. Anti-Reflective coatings are made of several layers of very hard thin film metal oxides that are layered on the lens surface. Each of those layers is chemically engineered to block reflected light by imparting an index of refraction that is somewhere between the index of refractions of air and glass. This causes the intensity of the light reflected from the inner surface and the light reflected from the outer surface of the film to be nearly equal, cancelling each other out through destructive interference and eliminating the glare. This increases the amount of visible light available to the eye thus improving the efficiency of vision.
You should not consider your eyeglass lenses complete unless they have anti-reflective (AR) coatings. Anti-Reflective coatings eliminate most surface reflections in eyeglass lenses (internal and external) - reflections that are both cosmetically unappealing (reduced eye contact) and can interfere with your vision.
Research has demonstrated that lenses with anti-reflective coatings provide better vision than identical lenses without anti-reflective coatings. Studies also show that people tend to be more comfortable working at a computer when wearing lenses with anti-reflective coatings compared to the similar lenses without anti-reflective coatings.
Anti-Reflective coatings on your glasses serve many purposes. An anti-reflective coating can be beneficial when driving at night. It reduces glare and "ghost images" from lights, as well as reduce eyestrain caused by overhead lighting. Often, individuals who wear glasses or contacts experience a halo effect around headlights and streetlights when driving in the dark. An anti-reflective coating eliminates this effect and can make night driving less of a distraction.
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. Anti-Reflective coatings can reduce eyestrain and make it possible to work on the computer for longer periods of time without difficulty. If you experience eyestrain, no matter the reason, anti-reflective coatings on your glasses may be able to help.
AR coatings on glasses also provide increased cosmetic appearance, particularly when taking photographs while wearing your glasses. With glasses that do not have an anti-reflective coating, outside images tend to be reflected by the glasses and block out the wearer's eyes. Anti-Reflective glasses ensure your eyes are seen.
Anti-Reflective coatings also enhance the quality and expand the lifetime of your eyeglasses by providing superior scratch resistance, durability and resistance to dirt, dust, water and smudge.
| |
Dennis Taylor
Subtractive Method
1902 |
Carl Zeiss
Patent
1940 |
 |
 |
1871
Joseph von Fraunhofer
Chemical Reaction
Caused Increased
Light Transmission |
1935
Dr. H. Smakula
Additive Method |
1978
Some of First
AR Applied to
Plastic Lenses
In USA |
|
Hydrophobic and Oleophobic coatings are basically top layer coatings applied to protect the Anti-Reflective coatings. This protection is provided in the form of repulsion properties and imparting a high contact angle to any fluid adhering to the surface of the lens. This helps the moisture and oil to slip away easily from the lens surface keeping the lens smudge free and cleaner for a longer period of time.
