-by Dr. Luke Small, Optometrist
Screen time. These two words have become ubiquitous at our house as of late. That’s because if we let our 10 and 8 year old kids choose their own amount of “screen time” they would go all day and all night.
As parents and as eye care professionals, my wife and I get caught having to wear two different hats when it comes to the perils of screen time. As parents it’s hard not to let the screens become babysitters as we try to keep up with our own busy lives. We also both love being outdoors and it’s often a battle getting the two of them off the couch when they could be playing MineCraft or binging on Kids Netflix. As optometrists, we get asked nearly every day by parents to counsel their kids about the ill-effects of screen time and how it’s going to ruin their kids’ eyes for the rest of their lives. Their hope is that hearing the doctor back them up will help to convince their kids to finally listen to them when it comes time to get off their iPad.
So how much screen time is too much and what are the potential long-term effects? I’ve spoken a lot about Computer Vision Syndrome (CVS) and although there are no proven long-term effects there are lots of short-term issues. Dry eyes, eyestrain, headaches and blurred vision are a few of the symptoms that come to mind. However, these symptoms rarely come up in kids as their eyes have a much better capacity to focus (what we call accommodation) for long periods of time compared to their parents.
Lately, we are getting asked more and more about the effects of blue light also known as HEV (High Energy Visible) light. This particular light falls in the range of 380nm to 500nm and is often derived from our screens (monitors, laptops, tablets, smart phones, etc…) and certain indoor lighting. Blue Light has been in the media more lately not based on the effects on eyes, but more so for the effects on our melatonin levels. Melatonin is a hormone that helps us sleep. Studies have shown that looking at screens that expose us to blue light can affect our normal sleep patterns and this is why we have all heard that it’s important that we shut down our devices at least an hour before bed. But then how am I supposed to finish my favorite shows on my Red Bull TV app? Practice what I preach should be the answer.
So what about our eyes and our children’s eyes when it comes to Blue Light (HEV?). Certain studies have shown that HEV light can create oxidative stress on the retina potentially contributing to Age Related Macular Degeneration (AMD). Oxidative stress poses an increased risk to damaging retinal cells and the macula is particularly sensitive to this type of stress. Reviewing these studies I don’t think there is enough proof yet to say there is a cause and effect relationship between Blue Light and AMD. There are numerous other risk factors such as nutrition, systemic health, smoking and genetics that play larger roles. Having said that, it is important to be aware of this stress on retinal cells and this leads the discussion to Blue Light Filters.
One way to decrease the effects of HEV light from our screens is to simply reduce the amount of screen time, but this is easier said than done. I have lots of patients over 80 years old who can spend hours on their tablets playing card games and watching their favorite videos. Tablets and laptops have also become popular teaching tools in all schools so it’s becoming harder and harder to avoid. Therefore the need for effective protection from Blue Light is become increasingly apparent. Most lens companies now all have their own version of a blue light filter. Not only do these act a scratch-resistant (notice that I didn’t say scratch-proof!) and anti-reflective coating, but will also filter out the spectrum of light that is HEV. At Armstrong & Small Eye Care Centre we’ve been offering these filters for a few years now and personally it has helped to decrease my own physical visual discomfort when I’m on my computer for long periods of time.
We’ve now had a few parents who have requested glasses with these filters even though their children don’t require any prescription when viewing their devices. This is a personal decision for each parent and may become increasingly popular depending on future results of more studies on the ocular effects of Blue Light.
For parents and particularly for those of us over 40 years old, we find that we are doing more and more “task specific” lenses which are designed to help those of us with more birthdays view our desk, computer and near work with much greater ease than our typical progressive lenses. We’ve had a lot of success reducing Computer Vision Syndrome by offering our patients this option where the majority of the top part of the lens is set for roughly arms-length away and the lower part of the lens is set for closer reading distance. These work particularly well for those of us who spend much of our day at a desk. We now make most of these lenses with a blue light filter included and have had great feedback from our patients meeting their visual demands head on and reducing their symptoms.
Times are forever changing and our dependence on screens and therefore our exposure to Blue Light isn’t going away anytime soon. We attempt to limit our own kids to an hour of screen time per day (usually way more on weekends unfortunately). For some parents this is way too much for others this would seem way too little. That decision is up to each individual parent, but knowing the issues of Blue Light exposure is a step in the right direction.