Anti-reflective coating (AR) is a type of Optical coating applied to the surface of lenses to reduce reflection and glare. This improves the efficiency of lenses and clarity of vision. The coating does just what the name implies: it decreases the reflection of light from the front and/or back of the lenses.Additionally, AR coatings increase the transmission of light through the eyeglass lenses. Modern coatings have the capacity to essentially completely eliminate the amount of glare experienced by those who wear glasses. A high-quality AR or anti-glare coating will allow 99.5% of light to pass through the lenses, allowing for better vision.
Ophthalmic lens coatings generally fall into four categories. The lowest layer closest to the lens surface is an impact-resistant coating. Above this is a hard coating, which protects the lens from scratches. The outermost layer is a water-repellent coat that prevents smudges from forming and allows easy cleaning of oil films caused by fingerprints. It also minimizes scratches created by repeated wiping, dust and nearly-invisible grains of sand. Between the hard coat and water-repellent layer are anti-reflective (AR) coats, crucial for the lens to achieve clear vision.
Advantages of Anti-Reflective Coating:
- Night time driving vision improvement by glare reduction, particularly on rainy nights;
- Glare reduction from computer, cellphone, and television screens;
- Improves appearance by making lenses seem virtually invisible;
- More photogenic as result of glare reduction on lenses; and
- New hydrophobic AR coatings resist smudging, making cleaning easier.
Patients with a stronger prescription in need of high-index lenses will find more benefit from anti-reflective coating as high-index lenses reflect more light than regular plastic lenses.The higher the index of refraction of the lens material, the more light that will be reflected from the surface of the lenses. AR coating greatly enhances the vision of those with a stronger prescription.
Anti-reflective coating can be applied to any kind of ophthalmic lens. For example, glass, plastic, high-index, poly-carbonate, sunglass lenses, and “Transition” lenses, will benefit greatly from AR coating. Interestingly, when it comes to sunglasses, AR coating is typically applied to the back surface of the lenses, eliminating reflection of the eye and objects behind the wearer.
Anti-reflective and anti-glare coating help wearers who experience visual strain caused by screen-use. The advancement of handheld devices and LCD displays has put every age group at risk of harmful blue lightexposure. Blue-violet light is harmful to retinal cells and is one of the risk factors for age-related Macular degeneration (AMD). Besides simply reducing glare, companies like Nikon and Essilor have developed AR coatings such as Nikon Seecoat Blue and Crizal Prevencia which block blue light and help to reduce eye fatigue.
In Japan, over 80% of eyeglass lenses include AR-coating. And, in most European countries, over 50% of glasses wearers have an anti-glare coating on their lenses. Yet, in the United States, less than 25-30% of lenses have anti-reflective coating. Although firm statistics aren’t known regarding Canadian patients and AR coating, the percentage of users seems to hover between 50-75%.
Despite these higher numbers, there is still room for improvement. Anti-reflective and anti-glare coatings are a positive and necessary addition to your eyecare regimen. During your next visit to your optician, ask about the different kinds of AR-coatings and how they can benefit you and your lifestyle.
You have only one set of eyes, without any spares; take care of your vision.
Vincent Afrouzi, R.O.