About one-third or 30 percent of human life is spent working. It’s safe to say that in today’s day and age that means a tremendous amount of time staring at a screen. Extended screen time and continuous exposure to blue light can lead to disrupted sleep, blurry vision, eyestrain and even macular degeneration. All of this overuse of screen time, continuous exposure to blue light and poor quality of sleep could be the culprit behind decreased productivity while working. In fact, tired eyes can lower a worker’s productivity around 15 minutes of work per day. While that might sound like a small amount of time to lose, that 15 minutes per day sums to more than 65 hours of productivity lost over the course of a year.
According to ophthalmologist Dr. Kara Hartl, M.D., F.A.C.S., quantity and quality of sleep can absolutely affect our work performance. During this past year due to COVID-19, the amount of screen time and reliance on technology has been through the roof. While it’s unlikely we will be able to totally power down from our various devices, it’s important to be more conscious about the long-term effect of blue light on our eyes and our bodies.
We caught up with Dr. Hartl to learn more about the effects of blue light on our vision and what steps we can take to take better care of our eye health.
Live Naturally: What are some of the most concerning long-term effects of blue light on our vision?
Dr. Kara Hartl: Blue light slowly damages our retina, the cells that turn light into vision. The high-energy blue light waves are not blocked the way UV rays are, and they penetrate straight into the eye. These cause oxidative damage to the photoreceptors similar to macular degeneration, one of the leading causes of blindness. This is dose-dependent and results from chronic exposure over many years and is irreversible. The only option we have is to prevent it.
LN: How does blue light affect sleep?
KH: Blue light exposure in the evening alters our natural circadian rhythm, and this changes the biochemistry in our brains. Sleep is the way our bodies repair the daily stresses of life, from forming long-term memories to repairing our DNA and preventing heart disease and cancer. Blue light blocks the production of natural melatonin and alters both the quantity and the quality of our sleep. The resulting damage to the body is widespread and includes immediate symptoms such as poor memory formation, slowed thought process and reflexes, as well as long-term consequences such as anxiety, depression, diabetes, heart disease, stroke and cancer.
LN: What is your 20/20/20 rule?
KH: The 20/20/20 rule recommends that every 20 minutes, you take a break from the computer, shift your eyes to look at an object (ideally, 20 feet away) and for 20 seconds. I would also recommend taking a walk outside or putting your computer down for a bit to give your eyes a screen break. If this proves to be a challenge for your schedule, try using computer glasses. These are basically a weaker reading glass set for more intermediate distances, for example +1.50 to +1.75. This will help relax the muscles that are focusing up close on your screen all day. Using lubricating eye drops (artificial tears) can help combat the fact that you blink less while reading or on the computer. Schedule these 4-6 times per day to stay ahead of the dry eye. Using a blue-blocking screen cover will help with this as well.
LN: While parents are at their computers a lot for work, what about the concerns/effects on kids who stare at screens too long?
KH: Right now, the level of screen time is off the charts and sadly, it might not be feasible at this moment to cut down on screen time (between virtual schooling and everything in between). Investing in screen protectors for your children’s computers or tablets is crucial (especially if you have young children, this is easier than getting them to wear blue light blocking glasses). Pay attention if your children mention headaches, dry eyes or irritated eyes. Activating night mode on your children’s computer, phone and tablet can also help, since night mode decreases screen brightness and reduces eye strain in the process. Additionally, there are apps that help keep track of your screen time.
LN: Along with the 20/20/20 rule, what advice can you offer to help reduce the effects of blue light on vision? For example, special filters?
KH: The effects of blue light are two-fold: The damaging effects to your eyes are in the higher energy rays and can be blocked all day long with a screen cover. This is the easiest solution and offers a “one-and-done” answer to preventing blindness. Your sleep cycle is controlled by a very specific spectrum and should be “turned on” in the morning and “turned off” in the evening, just like the sun. Bright sunlight, rich in blue light, helps you wake up. This same light in the evening prevents you from going to sleep, and it’s this effect that your LED screens mimic with the blue light waves. Using the night mode in your computer, tablet or phone can help to some degree. There are downloadable apps that do an even better job. But this is where real blue-blocking glasses come into play. In order to protect your circadian rhythm, you really need to block the blue light and this makes the world look yellow. There is no way around this, whether from light emission on your screen or with yellow glasses.
Blue light is not always a bad thing, and in the mornings, blue light helps us feel more alert, stimulates our body to wake up and energizes us. But it’s important to try and keep our blue light exposure in moderation. If it’s hard to take a step back from your devices, now is the time to invest in protective covers for your computer screen, phone and tablet. They offer a “one-and-done” solution, which makes them the easiest measure you can put into place. You apply them to the computer or device, and that’s where they stay. Additionally, there are a number of affordable blue light blocking glasses out there – just make sure that they actually block the blue light! The glasses should be very yellow, and give everything a yellow-ish tint.
LN: To maintain healthy vision, do you ever recommend supplements and/or certain types of foods?
KH: Aim for lots of green, leafy vegetables such as kale and Swiss chard, and include fruits and vegetables with lutein and zeaxanthin, like pumpkin, carrots and sweet potatoes. They provide necessary pigments in your eye to naturally protect from the effects of blue light on your retinal cells, but they don’t help protect your circadian rhythm. If you just can’t get the right foods in, taking lutein and zeaxanthin supplements will help as well.