Essilor, the manufacturers of Crizal products and other leading spectacle products like Transitions, Varilux and EyeZen, created a partnership with the Paris Vision Institute in 2008 with the objective of identifying the bands of visible light that were the most harmful to the human eye.

The researchers split the visible light into multiple bands of 10 nm and each band was then focused on porcine retinal pigment epithelial (RPE) cells for several hours. Using this method, the specific band of blue light most harmful to the retina and to the RPE cells was identified to be between 415 nm to 455 nm.

The blue-violet light that was discovered as part of this study is a 40 nm band of visible light that causes the maximum retinal cell death. Over time, our eyes are exposed to various sources that emit this blue-violet light (e.g. the sun, LED lighting, and fluorescent lighting). Combine that with the use of iPads, tablets, TVs, computer screens and smartphones, and there’s no doubt our exposure to blue-violet light is dramatically on the increase. This cumulative and constant exposure to the blue-violet light over time has the potential to cause serious damage to the retinal cells, which may gradually lead to retinal cell death, and can in turn lead to AMD: age-related macular degeneration.

The level of light emitted by newer energy-saving lighting techniques (e.g. LEDs and CFLs) is very high. These devices emit high levels of blue-violet light compared to the rest of the blue light spectrum. This underscores the need for us to protect our eyes from the harmful bands of blue-violet light.

The Good Side of Blue Light

Not all blue light is bad. The labeled blue-turquoise light range, which is from 465 nm to 495 nm, is essential to our vision, the function of our pupillary reflex, and in general to human health. It also helps to regulate our Circadian sleep/wake cycle.

So blue light in general can have healthy effects on vision as well as the body, and it is this blue-turquoise light that tends to have these beneficial effects. Inadequate light exposure means inadequate blue-turquoise light, which can throw off our Circadian biological clock and our sleep/wake cycle. This blue-turquoise light really plays a vital role in the general health of the individual.

Protection from UV and Blue-Violet Light

How can we block the harmful blue rays of light but allow the helpful blue-turquoise rays of light to penetrate through and get into the eye?

Essilor has specifically developed Crizal Prevencia lenses with a selective light filter that blocks out the harmful blue-violet light… but allows the blue-turquoise light and the longer wavelengths of light to pass through it.

Crizal Prevencia has a patented, selective, no-glare technology with three key features: 1) it selectively filters out harmful blue-violet and UV light, 2) it allows the beneficial visible light, including the blue-turquoise light, to pass through and 3) it maintains an excellent transparency of the lens, so there’s no color distortion and you get excellent clarity with the lens.

Crizal Prevencia also provides protection from UV and Blue Violet light that could reflect back into the eye, protecting the wearer from the reflective glare that comes off the back surface of the lens.

The traditional blue light blocking lenses do not discriminate in the blue light spectrum. They block out all the blue light. Crizal Prevencia lens technology is based on laboratory studies over a 6-year period of time by a world-leading group of scientists as well as clinicians who discovered vital data that allowed them to zoom in on the light that needed to be blocked and the light that needed to get through. Crizal is the only brand which can offer this technology.

Who’s going to need the most protection?

Those who have high exposure to white LED or fluorescent light bulbs in offices and homes, frequent users of LED computer monitors, tablets, or smartphones, and those at risk for AMD (for example, those with family history of the condition).