Blue Light And Your Eyes – All You Need To Know

Are your eyes frequently dry and irritated? Do you have sudden headaches, especially after working on your computer? Trouble sleeping after a long day in front of the various screens that are part of our daily lives?

It could be the light. The blue light, to be more specific.

Several studies have firmly established that the light emanating from computer, tablet and cell phone screens is damaging to our health in a variety of ways, starting with our eyes.

But now there’s a way to prevent the damage.

Let’s first understand why long, unprotected periods of looking at screens can be a serious health issue.

We are exposed daily to light from a variety of sources, with diverse characteristics:

Daylight /sunlight provides the full spectrum of colors, including ultraviolet and infrared, invisible to humans. A healthy dose of sunlight is essential to our health – think calcium, vitamin D, strong bones –  but studies over the past decades have shown that ultra violet rays damages skin cells and contribute to the development of skin cancers and cataracts. The harmful ultra violet can be managed with sunscreen and good sunglass lenses, which block UV, enhancing the natural ability of our eyes to filter UV light. 

The good ol’ incandescent light provided by regular light have minimum effect on eyes and skin. They are going the way of the dinosaur, though, and are being replaced by more the more energy-saving halogen, LED and fluorescent bulbs.

Fluorescent bulbs and cool white LED sources of light have the higher amount of blue light , also known as Higher Energy Visible light, or HEV, close to UV and known to impact skin and eyes. Fluorescent bulbs have about 25% of blue light, while LED – present in computer screens, tablets, TV and most smartphones – have as much as 35% of HEV.

Over the past two decades, more sustainable, but also more HEV-intense, light sources are now the rule in our daily lives. On top of that, the use of LED screens, once restricted to a small group ops users, has become widespread. Can you imagine a common day in your life without looking at a cell phone, TV or computer screen?

Scientists have been tracking the impact of these changes on our health. And the results are worrisome: in terms of vision alone, HEV contributes to retinal disease, lenticular disease and ocular surface disease. Dr. Francine Behar-Cohen, founder of the INSERM (French Institute of Health and Medical Research) states that HEV light has long been identified as the most dangerous light for the retina. “After chronic exposure, one can expect (long term) growth of macular degenerations, glaucoma and retinal degenerative diseases.” Research has also indicated that cumulative lifetime exposure to blue wavelength light increases the risk of age-related macular degeneration (AMD).

And that’s just the impact on our eyes – Harvard researchers conducted an experiment comparing the effects of 6.5 hours of exposure to blue light to exposure to green light of comparable brightness. The blue light suppressed melatonin for about twice as long as the green light and shifted circadian rhythms – the “internal clock” that tells us when to go to sleep and when to wake up – by twice as much (3 hours vs. 1.5 hours). In a separate study. Short or irregular sleep can lead to increased risk of depression, diabetes and cardiovascular problems.

Since screens are going nowhere, what can we do to protect ourselves. Planning a healthy regimen of cycles with and without looking at screens is a good start.

Getting the right lenses – even if you don’t need corrective glasses – is a powerful resource with immediate results. 

Working with scientists who have been studying the impact of HEV on human vision, several optical companies have created coating and lenses that effectively block harmful blue light from ever reaching the eye.

SeeCoat Blue is a coating specifically designed to filter HEV light. Applied on the front and back of lens, it effectively eliminates a large portion of harmful blue light in the 380-500m nanometers range. Besides protecting the eyes, SeeCoat Blue also improves contrast and reduces ocular stress, and it’s also anti-scratching, anti-glare and anti-static. 

Essilor, makers of the widely prescribed Crizal lenses, has just come out with Crizal Prevencia, the first clear lenses which protect the eyes against both UBV and Blue-Violet (HEV) light. The lenses are perfectly clear (if you want to check whether they are “legit”, just rotate the glasses under a light source, and you’ll see a violet reflection at the edge of lens); and yet, they are doing the job of being a barrier between your eyes and the unsafe violet-blue light, all the while giving you crisper vision and preventing eye strain.

Would you go out in the sun (or snow) without sunscreen? Re-think your glasses as sunscreen for your eyes. They will thank you.