Most of us know not to look directly at the sun, yet we stare at computer screens that emit the same sort of rays
As the summer winds down and our focus shifts from fun in the sun to getting back to the grind, now is the perfect time to also shift our thinking about how we protect our eyes. In the warmer months, we are all aware that UV rays from sunlight can be harmful to our eyes, so we put on our favourite pair of stylish shades and head out into the world knowing that we’re doing the right thing for our eye health (while also looking great, of course).
But as the seasons change and we head back to school and work, we will be spending far less time outdoors yet more time being exposed to a different sort of light that can also be detrimental to our eye health. The screens on all of the digital devices we commonly use throughout our day (phones, tablets, computers, flat screen TVs, et cetera) emit a type of high-energy light often referred to as blue light.
High-energy blue light is actually all around us, and the largest source of it is sunlight. In fact, because these short-wavelength rays scatter more easily when they travel through air and water, blue light is what makes the sky look blue. Blue light is also essential to our health. Studies have shown that exposure to blue light is important in regulating our circadian rhythm (our wake and sleep cycle). In this way, it boosts alertness, helps cognitive ability and elevates mood.
However, in recent years, our increased use of computers and digital devices has brought us much closer to artificial sources of blue light. Now, the number of hours we spend exposed to blue light on a daily basis makes it a true concern for our health and wellbeing.
From a visual comfort perspective, blue light is quite disruptive. Because high-energy light scatters more easily than other visible light, it is not as easily focused by our eyes. This can lead to digital eye strain, which can result in fatigue, blurred vision and headaches. The effects of blue light on our overall health can be wide-ranging. The primary concern, as researchers at Harvard University and many other institutions have shown, is that increased exposure to blue light in the evening can disrupt our circadian rhythm, which can lead to poor sleep patterns. Also, it’s been well documented that a lack of sleep can ultimately increase the risk for significant health concerns such as depression, diabetes and cardiovascular problems.
With our work and personal lives progressively becoming more immersed in the digital world, it’s hard to recommend a complete ban on digital devices. However, the simplest thing we can do to improve our visual outcome is to decrease unnecessary screen time. This step is particularly important for the younger generation. The Canadian Association of Optometrists and the Canadian Ophthalmological Society recently released a joint statement recommending no more than two hours of recreational screen time for children aged five to 18. The same statement also strongly recommends limiting screen time at least one hour before bedtime to allow our sleep cycle to activate fully.
For those of us who must spend time in front of screens, there are ways that we can more actively protect our eyes against the harmful effects of blue light. Advances in optical lenses have provided a great new option to help us filter out the high-energy light that would otherwise penetrate the front of our eyes and potentially result in digital eye strain. These lenses, which we generally refer to as blue-blocking or blue-filtering lenses, are a great option for anyone, young or old, who spends time in front of screens.
As we continue to integrate digital devices into various facets of our lives, it’s vital to remember the potential effects that these new technologies can have on our health. Protecting our eyes today can allow us to preserve our vision in the future.
Dr. Harbir Sian completed a BSc in kinesiology from SFU in 2005, then moved to Boston, where he obtained a doctor of optometry degree at the New England College of Optometry in 2010. Since graduation, he has practised in the Lower Mainland.
Sian operates two optometry offices, Clarity Eyecare in Surrey and Highstreet Eyecare in Abbotsford. He also looks for ways to promote the importance of eye health, writing blogs, making YouTube videos and participating in volunteer eye clinics in North and South America. In 2016, BC Doctors of Optometry named him Young Optometrist of the Year.