In this video, Charlie Saccarelli from Chadwick Optical debunks common myths surrounding Anti-Reflective (AR) coating, helping you distinguish between aesthetic benefits and actual visual performance.
Reflection vs. Glare
The terms are often used interchangeably, but functionally they are quite different in the world of optics:
- Reflection: Light bouncing off a surface and becoming visible. This is primarily an aesthetic issue where others see light on your lenses rather than your eyes.
- Glare: Light that is bothersome or interferes with your vision, such as headlights while driving at night.
- The Myth: Advertising often suggests that because AR coating makes lenses look clear to an observer, it provides the same dramatic “anti-glare” clarity to the wearer.
How AR Coating Works (The 8% Rule)
Every uncoated lens surface reflects approximately 4% of light. Since a lens has two surfaces, about 8% of light is reflected away.
- Looking In: An observer sees that 8% reflection, which is why uncoated lenses look shiny or mirror-like
- Looking Out: You lose 8% of light transmission, but you don’t actually see the reflections from the front of the lens
The most significant visual benefit for the wearer comes from reducing back-surface reflections. Without AR coating, light from behind you (like the sun or a lamp) can hit the back of your lens and reflect directly into your eye, acting like a partial mirror. This is the primary source of functional glare that AR coating eliminates.
Compounding Reflections: Multi-Lens Systems
While AR coating offers a subtle benefit for a single pair of glasses, its importance increases exponentially when you use multiple optical layers.
- Single Lens: 8% of light is reflected
- Lens + Clip-on: Light must pass through four surfaces. The reflections begin to bounce between the two lenses, creating “ghost images” and significant visual noise
- Multi-Lens Optics: This is why high-end camera lenses, which often contain 5 to 10 glass elements, require heavy AR coating to maintain contrast
The Verdict: Is it a Scam?
While AR coating is not a scam, it is often oversold.
- Aesthetics: 10/10. It makes your glasses look much better and allows people to see your eyes
- Night Driving: The “halo” reduction seen in ads is largely exaggerated. You will see a slight improvement, but it isn’t life-changing for most people
- Functionality: If you use clip-ons or have light sources frequently behind you, AR coating is highly recommended to stop back-surface “mirroring.”
Charlie Saccarelli
President, Chadwick OpticalAs President of Chadwick Optical, Charlie Saccarelli is the driving force behind the company’s mission to help every patient left behind by the current health care system. Under his leadership, Chadwick has grown from a simple optical lab into a trusted resource for practitioners around the world looking for ways to help the patients that “can’t be helped.” He is a master optician, a father, a bit of a nerd, and a passionate patient advocate who has lectured worldwide on all things optical.