In this video, Charlie Saccarelli from Chadwick Optical breaks down the common misconceptions regarding anti-reflective (AR) coating, specifically addressing why “night driving” marketing images are often misleading.
The Cosmetic vs. Visual Reality
The most immediate benefit of an AR coating is cosmetic. Without the coating, people looking at you see reflections on the surface of your lenses rather than your eyes.
- Cosmetic Benefit: It allows others to see through the lenses to your eyes with minimal reflection.
- Visual Fallacy: Marketing images often imply that because the lens looks clear from the outside-in, the view from the inside-out must be drastically improved. However, the physics of light tells a different story.
The Physics of Light in a Lens
Charlie explains that the amount of light lost to reflection in a standard lens without AR coating is relatively small:
- Light Transmission: Roughly 92% of light passes through a standard lens to the eye.
- Surface Reflection: Approximately 8% of light is lost to reflections (roughly 4% off the front surface and 4% off the back surface).
- Glare Perception: The amount of “ghost images” or internal glare that actually reaches the pupil is a tiny fraction of a percent (4% of 4% of 4%).
Because such a small amount of internal reflection reaches the eye, the “glare reduction” experienced by the wearer is far less dramatic than the glare reduction seen by an observer looking at the glasses.
Tips for Better Night Driving
If you are struggling with glare and halos while driving at night, Charlie suggests several practical steps that often yield better results than just adding an AR coating:
- Clean Your Windshield: Haze on the inside or outside of a car windshield is a primary cause of halos and glare
- Clean and Inspect Your Glasses: Scratched lenses or lenses with a film of oil/dirt will catch light and create significant visual noise
- Consider a Light Tint: For those still bothered by bright headlights, a light tint (such as yellow to maintain brightness perception or a light gray) can help reduce the overall intensity of the light entering the eye
While anti-reflective coating is excellent for making your glasses look better and reducing mirror-like reflections on the back of the lens, it is not a “magic bullet” for night driving glare. Maintaining clean optical surfaces—both on your face and in your car—is your first line of defense for clear night vision.
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.
