Strong surface reflections can obscure the eyes and can be distracting around bright lights at night.
Anti-reflective coating is designed to reduce unwanted reflections at lens surfaces and increase useful transmission.
01 · SURFACE REFLECTION
Some light reflects at each lens surface
Whenever light crosses between air and lens material, a portion is reflected. Uncoated reflections can be more noticeable with higher-index materials.
Surface reflection naturally occurs at a boundary between materials with different refractive indices, such as air and a spectacle lens. The amount also varies with wavelength and angle of incidence, and uncoated high-index substrates can show more noticeable reflections. Because light crosses both front and back surfaces, these reflections can affect both appearance and internal ghost images.
02 · INTERFERENCE
Thin-film interference is used to suppress reflection
Multiple thin layers are engineered so reflected waves partially cancel across selected wavelength ranges.
AR coatings use phase differences between reflections from thin optical layers so that part of the reflected light cancels. Suppressing one wavelength is relatively simple; keeping reflection low across much of the visible spectrum and over useful angles requires multilayer design. Real coatings are therefore optimized low-reflection systems, not literally reflection-free surfaces.
03 · TRANSMISSION
Reducing reflection can increase transmission
With less light reflected away, more light can pass through, and the wearer’s eyes are also easier for others to see.
Reducing light that is reflected away can increase the fraction transmitted through the lens and makes the wearer’s eyes more visible to other people. That does not improve the measured prescription or automatically solve every contrast and glare complaint. The core job of AR is to reduce unwanted reflection generated by the lens surfaces themselves.
04 · NIGHT USE
The effect can be noticeable around point lights at night
AR can reduce reflections generated by the spectacle lens itself around streetlights and headlights, but it cannot remove the light source or all scatter inside the eye.
At night, small bright sources such as headlights appear against a dark background, which can make residual lens reflections and ghost images easier to notice. AR can reduce those surface reflections, but it cannot remove scatter inside the eye, dry-eye effects, a dirty windshield, vehicle-glass reflections or the intrinsic brightness of the light source. “Night glare reduction” should therefore not be interpreted as a cure for every night-driving complaint.
05 · RESIDUAL COLOR
Residual color is part of coating design
Not every wavelength can be reduced to zero reflection, so green, blue or violet residual reflections may remain. Color alone is not a complete quality grade.
The green, blue or violet residual reflection seen on many coated lenses is a result of the spectral design rather than proof of a good or bad coating by itself. Different products distribute residual reflection differently across wavelengths. Useful comparisons include measured reflectance/transmittance, durability and cleanability instead of ranking coatings by residual color alone.
SOLUTION GUIDE
Solution guide
Reduce reflections from the lens surfaces.
Increase useful light transmission.
Make the eyes more visible behind the lenses.
Reduce spectacle-surface reflections.
Compensate for stronger uncoated surface reflection.
GLANOS LENS CHECK
Do not equate antireflection with eliminating all glare
Visual discomfort can also come from the eye itself, the environment and other optical conditions. In this lens series, index, material, design and coating are not treated as independent quality grades; each is evaluated in the context of prescription, frame geometry and actual wearing conditions.
CAUTION
AR coating is not a universal cure for night vision problems
Its main role is reducing reflections generated at the spectacle lens surfaces. Material chemistry, design rules, minimum thickness and coating architecture vary by manufacturer and product, so a value or feature from one lens should not be generalized to all spectacle lenses.
GLANOS EYEWEAR
There is a reason glasses feel uncomfortable.
anti-reflective · AR coating · night vision · lens reflection · high index · eyeglass lenses