Editing Corrective lens (section)

== Lens coatings ==
{{Main article|Optical coating}}

=== Anti-reflective ===
[[File:Anti-reflective coating comparison.jpg|thumb|The effects of an anti-reflective coating applied (as seen on the bottom picture) as compared to regular eyeglass lens (notice how the reflection of the photographer in the top lens is clearly visible)]]
{{Main article|Anti-reflective coating}}
Anti-reflective coatings help to make the eye behind the lens more visible. They also help lessen back reflections of the white of the eye as well as bright objects behind the eyeglasses wearer (e.g. windows, lamps). Such a reduction of back reflections increases the apparent contrast of surroundings. At night, anti-reflective coatings help to reduce headlight glare from oncoming cars, street lamps, and heavily lit or neon signs.

One problem with anti-reflective coatings is that historically they have been very easy to scratch. Newer coatings try to address this problem by combining scratch resistance with the anti-reflective coating. They also offer a measure of dirt and smudge resistance, due to their [[hydrophobe|hydrophobic]] qualities. {{citation needed|date=August 2016}}

=== Ultraviolet protection ===
A [[UV coating]] is used to reduce the transmission of light in the [[ultraviolet]] spectrum. [[Ultraviolet|UV-B]] radiation increases the likelihood of [[cataracts]], while long-term exposure to [[Ultraviolet|UV-A]] radiation can damage the [[retina]]. DNA damage from UV light is cumulative and irreversible. Some materials such as [[#Trivex|Trivex]] and [[#Polycarbonate|Polycarbonate]], naturally block most UV light; they have UV-cutoff wavelengths just outside the visible range and do not benefit from the application of a UV coating.{{Citation needed|date=January 2009}} Many modern anti-reflective coatings also block UV.

=== Scratch resistance ===
Resists damage to lens surfaces from minor scratches.