The sun is the ultimate provider of all life on Earth but, as anyone who has ever fallen asleep on a summer beach knows, it can also be incredibly dangerous. Just as too much sun on our skin can cause sun burns and eventually cancer, too much sunlight in our eyes can cause a host of vision problems as we age. The main culprits are ultraviolet (UV) light and blue light, which is worryingly ubiquitous both indoors and out.

“There are sources of blue light everywhere you look — everything from compact fluorescent lighting tubes to LED lights,” says Dr. Upen Kawale of Toronto Eye Care. “The biggest challenge is that we live in a digital age and every digital device — computers, tablets, smart phones, TVs — are all emitting blue light.”

The blue light that eye doctors are concerned about is a thin band of the visible light spectrum more specifically called blue-violet light. This is to differentiate it from the nearby blue-turquoise light band which is essential to vision, sleep cycle, and many other areas of human health. Similarly, UV light has a good side as well as a bad — being responsible for the production of vitamin D, a micronutrient essential to bone health.

“It took us years to get to the level of UV light awareness we are at now and that process is just starting with blue light.”

There’s just too much light in modern life

The problem is not that sunlight is bad for us — it’s that we are getting far more of the bad kinds of light than our ancestors did, and the effects of both UV and blue light are cumulative over time. We use devices all day and then turn on artificial lights at night. And, perhaps most importantly, we are living much longer. “As the population is getting older, we’re going to see the prevalence of these conditions increase,” warns Dr. Jerry Nolfi, also of Toronto Eye Care.

The conditions in question are cataracts, which can be caused by UV light breaking down proteins in the crystalline lens. Or, macular degeneration, which can be caused by blue light damaging the photoreceptors in the retina. While there are effective surgical treatments for cataracts, macular degeneration remains incurable and results in blindness in the central field of vision.

And yet, awareness of the dangers of blue light among the public is worryingly low. “It took us years to get to the level of UV light awareness we are at now and that process is just starting with blue light,” says Dr. Nolfi. It is imperative that we continue to educate people, and awareness campaigns like Blue Light Exposed — which expose the harmful effects of blue light rays — help achieve that goal.

To lower our risk of these conditions, Drs. Nolfi and Kawale suggest that we focus on the factors that are under our control. Certainly, genetics and aging can play a large role in whether we develop these eye conditions, but there’s nothing we can do about that. What we can do is stop smoking, maintain a healthy weight, and limit our exposure to blue and UV light.

“Anything that can reduce your blue light exposure is going to help. You can minimize your digital device time. You can wear eyeglasses with lenses that feature a blue-violet light filter coating. You can be proactive with wearing a hat and sunglasses,” says Dr. Kawale. “It’s especially worrisome with children, who are beginning to use tablets from a very young age, and we know that the effects are cumulative. Parents need to be aware that these risks are there and that they have control over them.”