AR Coatings of YesterdayYears ago, AR coatings may have seemed more like a hindrance than an advantage. Past problems included a constant need to be cleaned, peeling coating, and frequent scratching. Because of these problems, many patients tend to shy away from them when offered by their opticians. However, AR coating has seen several improvements over the past few years.
New and ImprovedThe new generation of AR coatings are tough, durable and provide superior vision. The word "coating" is really a misnomer. AR coating is actually fused or "baked" onto the lens matrix, unlike past versions.
Newer generation AR coatings also contain chemicals that make them hydrophobic, which means that the lens surface will reduce adhesion of water and grease. This keeps the lenses cleaner for a longer period of time and makes them much easier to clean when they do become dirty.
The Science Behind Anti-reflective CoatingAR was first developed to enhance and improve the view on high powered telescopes, microscopes and camera lenses. AR coating is composed of multiple layers of metal oxides applied to the front and sometimes the back surface of the lens. This layering affect reduces reflected light and allows more light to be transmitted through the lens.
What does this do for eyeglasses? First, it improves the appearance of your eyes to the outside world. AR coating makes the lenses appear almost invisible. It also vastly improves the cosmetic appearance of wearing the lenses by reducing internal reflections in the lens, making your lenses appear much thinner.
Secondly, it improves the quality of your vision by reducing reflected lights. This cuts down on glare and halos around lights, and improves the quality of your vision at night and when using the computer in certain work environments.
While AR coating is beneficial to everyone, it is found almost universally on high index lenses. High index lenses are made out of a type of plastic that can make your lenses much thinner than regular plastic lenses. However, to achieve this thinness, sometimes the lens material can cause unwanted reflections. As a result, manufacturers who produce very high index lenses make AR a part of the complete lens price and do not separate the lens from the AR coating because they believe a very high index lens should never be worn without an AR coating.
What You Need to KnowWhen choosing AR coatings, pay particular attention to the grading scale offered by your optician. Some opticals may offer a choice of "good, better and best," with the best grade being considerably more expensive. In my opinion, choosing a mid- or higher-end coating is well worth your money. Besides offering excellent vision benefits, they also carry better warranties and often may be replaced at no charge if your lenses scratch within a year. The lower cost choices usually do not contain the new and improved properties discussed above.
Some quality brand name AR coatings are:
- Crizal Alize' (Essilor)
- Crizal Avance' with Scotchguard (Essilor)
- Hi Vision (Hoya)
- Super Hi Vision with ViewProtect (Hoya)
- Teflon® Clear Coat (Zeiss)
- Carat Advantage (Zeiss)
Bruneni, Joseph L. "AR Plays Catch-Up." Eyecare Business, 2009.