The phenomenon of seeing your own eyes or the surrounding environment reflected in your glasses is common. This is not a manufacturing defect but a consequence of basic light physics interacting with the curved plastic or glass of the lenses. This optical issue has several effective solutions.
Why You See Your Own Eyes: The Optics of Internal Reflection
The reflection you are seeing is primarily caused by light sources that are behind you or to your side. This light travels past your head and strikes the back surface of your eyeglass lenses. A small percentage of this light is reflected off the lens surface and directed straight into your eye.
This process, sometimes called back-glare, creates an image of whatever is behind you, including the light source itself and, often, the area around your eye. The curvature of the lens material can act like a slight mirror, facilitating this internal reflection. Higher-index lenses, which are thinner and denser, tend to reflect a greater amount of light than standard lenses, making this issue more noticeable for people with stronger prescriptions.
The reflection is especially prominent when a bright light, such as an overhead office light, a window, or a computer screen, is positioned directly behind you. This unwanted light bounces off the inner side of your lens before reaching your pupil. While this is a minor annoyance for some, it can significantly reduce visual clarity and cause eye strain.
The Technical Solution: Anti-Reflective Coatings
The most effective and permanent solution for eliminating back-glare and seeing your own reflection is the application of an anti-reflective (AR) coating. An AR coating is a series of microscopic layers of metal oxides applied to the lens surface using a process called vacuum deposition. These layers are designed to reduce reflections on both the front and back surfaces of the lens.
The coating works through a process called destructive interference, a principle of wave physics. Light that reflects off the outer layer of the coating is intentionally made to be half a wavelength out of phase with light reflecting off the inner layer of the coating. When these two light waves meet, they effectively cancel each other out, which minimizes the reflection.
For this cancellation to occur, the thickness of the coating layer must be precisely controlled, often equivalent to about a quarter of the light’s wavelength. Modern AR coatings use multiple layers to cancel out reflections across a broad spectrum of light wavelengths, allowing up to 99% of available light to pass through the lens and into the eye. This improved light transmission eliminates internal reflection, enhances visual clarity, and reduces eye fatigue.
The importance of AR coating for internal reflections lies in its application to the back surface of the lens, which directly faces the eye. This prevents light from behind you from bouncing back into your eye. The coating also makes the lenses appear nearly invisible to others, improving the cosmetic appearance of the glasses.
Practical Ways to Reduce Reflection Visibility
While AR coatings offer the best defense, you can also make adjustments to lessen the visibility of reflections. Frame fit is important, as a properly adjusted frame can redirect reflections away from your line of sight.
A slight downward tilt of the lens, known as pantoscopic tilt, is an intentional adjustment that helps align the optical center of the lens with your typical gaze. This tilt ensures that the bottom of the frame is slightly closer to your face than the top, which can help angle potential back-glare reflections downward and away from your eye.
Environmental factors are also easily controlled, particularly when sitting at a desk or on a video call. Positioning light sources above and slightly to the side of your head, rather than directly in front of or behind you, can dramatically reduce the angle at which light strikes the lens. This simple change utilizes the physics of reflection, causing the light to bounce off at an angle that avoids your eye.
Adjusting the brightness of a computer monitor can also help, as a very bright screen can act as a light source that reflects off the back of the lens. Choosing a frame with a slightly larger lens size or a minimal “wrap” around the face can sometimes help physically block light entry from the sides, reducing the incidence of light hitting the lens’s back surface.