Anti-reflective (AR) coating is a specialized treatment, a multi-layered film applied to the front and back surfaces of an eyeglass lens. The primary function of this coating is to eliminate reflections and glare, which can otherwise cause visual distractions and eye strain. By suppressing reflections, the coating allows nearly all available light to pass through the lens and reach the eye, optimizing visual clarity. The technology uses carefully calibrated layers of metal oxides to achieve this effect, and there are simple, practical visual tests you can perform to verify its presence on your glasses.
The Residual Reflection Color Test
The most objective way to determine if your glasses have an anti-reflective coating is by examining the color of the residual reflection. Anti-reflective coatings work by using destructive interference, leaving a faint, characteristic reflection. To perform this test, hold your glasses at a slight angle toward a bright, concentrated light source, such as a lamp or a window. Observe the reflection on the lens surface as you slowly tilt the glasses.
If an AR coating is present, the reflections will appear as a subtle, identifiable color, rather than the bright, unfiltered white or yellow reflection seen on a non-coated lens. The color you see—most commonly a faint green, blue, or purple sheen—is the specific wavelength of light that the coating is designed not to neutralize. This specific color varies depending on the manufacturer’s proprietary formula. If the light reflecting off the lens is the same color as the source and appears strong or mirrored, the AR coating is likely absent.
Observing Light Transmission and Glare
You can also assess the presence of an AR coating by evaluating how the lens handles light transmission and glare. This method focuses on the practical benefits of the coating as you look through the lenses, rather than at their surface. Look directly at a concentrated light source, such as a computer screen, a bright overhead light, or an oncoming car headlight at night.
A lens with an effective AR coating will appear almost invisible, allowing maximum light to pass through with minimal visual interference. When looking at a light source, you should notice a significant reduction in distracting reflections on the inner surface of the lens. Lenses without this coating often produce noticeable “ghost images” or hazy halos around bright lights due to internal reflections bouncing off the back surface and into your eye. The reduction of these distracting internal reflections is a clear indication that the anti-reflective treatment is successfully working to enhance your visual comfort.
Ruling Out Confusion with Other Lens Treatments
It is important to distinguish the anti-reflective coating from other common lens treatments. For instance, UV protection is a treatment that shields the eyes from harmful ultraviolet radiation, but it is entirely invisible and cannot be verified by color or reflection. Similarly, a scratch-resistant coating, sometimes called a hard coat, is a durability treatment designed to protect the lens surface from damage. Neither UV protection nor scratch resistance will create the faint green, blue, or purple residual reflection that is the hallmark of an anti-reflective coating.