Crizal Prevencia lenses: How they work and where to buy
What is Crizal Prevencia?
Crizal Prevencia is a special preventive eyeglass lens treatment, known to simultaneously block ultraviolet and harmful blue light. It eliminates reflections from lens surfaces, reduces glare, resists smudges and scratches, repels water and dust, and protects against the potential damage caused by blue-violet light. It is quite comprehensive in its scope.
Lenses with Crizal Prevencia coating filter up to 25% of identified blue-violet light, while allowing beneficial blue light — blue-turquoise light — to pass through.
Harmful blue light vs. beneficial blue light
While information surrounding the dangers of blue light may have you convinced that all blue light is bad, it’s important to know that there are different types of blue light — some of which are beneficial.
The light spectrum is made up of different colors, each of which has its own wavelength, measured in nanometers (nm).
Colors on the warm end of the spectrum (red, orange and yellow) have longer wavelengths — approximately 580 to 700 nm — which means they carry less energy. Colors on the cool end of the spectrum (green, blue, indigo and violet) have shorter wavelengths of 400 to 550 nm, that carry higher energy frequencies. The higher-energy frequencies (the cool colors with shorter wavelengths) do more harm.
Blue-violet light has a wavelength of 415 to 455 nm and is close on the spectrum to ultraviolet (UV) light. Exposure to UV light is responsible for creating sunburns and skin damage that can lead to different skin cancers.
The greatest producer of blue-violet light is sunlight, though smartphones, tablets, computers and TVs also project it.
During a vision process known as phototransduction — where light hits the rods and cones in the retina and is turned into electrical signals — the eye absorbs greater amounts of blue-violet light than any other kind of light. Blue light can transmit through the cornea and lens within the eye to the back of the retina.
Some eye doctors and researchers fear that too much exposure to high-energy, blue-violet light over a person’s lifetime (from sunlight and prolonged use of digital devices) could damage the retina and possibly increase the risk of macular degeneration later in life. Long-term population studies are needed to know for sure, and no definitive research of this kind currently exists.
If you move away from UV light on the color spectrum and closer to green light, you’ll find blue-turquoise light. It has a wavelength of 465 to 495 nm and a much different effect on the eyes than blue-violet light.
Your circadian rhythm controls your wake and sleep cycles and relies on blue-turquoise light to stay on track. A balanced circadian rhythm keeps things such as your hormonal balance, mood and memory working as they should.
SEE RELATED: Blue light glasses test
How Crizal Prevencia lenses work
Crizal Prevencia lenses are the product of collaboration with the Vision Institute in Paris and years of studying photometry, cellular biology and physics. Through this, researchers were able to pinpoint which light on the color spectrum is most harmful to retinal cells and create a clear lens that effectively filters it.
Technology used to achieve this includes Light Scan, which selectively filters 20% of harmful blue light and 100% of UV light. The lenses are also equipped with back surface protection, so wearers aren’t exposed to UV rays reflected from the back surface of the lens.
Finally, Crizal Prevencia lenses are installed with the Eye Protect System — a feature that allows the lens material to absorb dangerous light waves rather than the eye itself. When paired with the Light Scan feature, the Eye Protection System can filter an average of 30% of blue-violet light.
In addition to blocking blue light, lenses treated with Crizal Prevencia have an eye-sun protection factor (E-SPF) of 35 — the highest UV protection level in a clear lens. The goal of this comprehensive lens treatment is to prevent future damage due to harmful ultraviolet and blue light exposure.
Where to find Crizal Prevencia lenses
Crizal Prevencia can be applied to most lens shapes, sizes and prescription strengths (including no prescription at all). However, you can only get new lenses with Crizal Prevencia; it cannot be added to existing lenses.
Many eye doctors, within the U.S. and internationally, offer Crizal Prevencia lenses in frames from their personal inventory. This search tool makes it easy to find local eye doctors who carry Crizal Prevencia lenses. You’re also given the option to filter your search to only show doctors who accept your insurance, making it a convenient method for finding a preferred Crizal Prevencia carrier.
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Crizal Prevencia: Blue light filter lenses. Essilor. Accessed August 2021.
The visible spectrum. Britannica. Accessed August 2021.
Understanding blue light. Retina Today. April 2016.
Phototransduction. Encyclopedia of Neuroscience. 2009.
Pupillary reflex - an overview. The Senses: A Comprehensive Reference. 2008
Essilor lenses - Crizal Prevencia. Essilor. Accessed August 2021.
Page published in September 2021
Page updated in January 2022
Medically reviewed in September 2021