Blue Light: A Deep Dive

Blue Light: A Deep Dive

The Blue Light Debate

 …and why it hurts to stare at a computer screen all day!

Blue light has become a big buzzword all throughout the industry and we’re seeing a huge uptick in patients coming in specifically asking for blue light protection. Most of these folks fall in to the same category of all day 8hr computer usage intertwined with breaks spend staring at a cellphone or magazine and then back to the computer, only to head home and stare at a screen till bedtime. 

Here are just a few of the plano blue light glasses we are making for our contact lens wearers.  

In keeping up with the literature I have seen blue light implicated in everything from changing your circadian rhythm to accommodative stress, eye fatigue, adrenocortical hormonal dysfunction, cataracts, macular degeneration, and beyond. The research varies greatly between research sources as does the quality of the research. I think it’s important to first understand a few take home points.

Primarily, most research completed involves blue light at a much higher level than you would generally encounter it, and for a much longer period of time. The last article read I stated the light was 5000 lumen, 24/7, for 7 days straight. A typical incandescent light of 150W only puts out 2600 lumen. You’re not about to stare directly into a 300w light are you? The other important thing to understand is that the sun puts out over 10x the amount of blue light than any digital device you use on a regular basis. Lastly, when you are using a digital device you are likely sedentary. We live an unfortunately increasingly sedentary lifestyle. 

With the groundwork laid, lets now focus on how we interact with digital devices and how they both interfere with our normal routines and interfere with standard physiology. Most adults look at a screen as both the first and last thing they see pre and post sleep. Our days are spent intently staring with ever decreasing font sizes in spreadsheets and brighter OLED screens. Often times we experience dryness, foreign body sensation, eye strain or fatigue, tearing, and so on and so forth.To understand the underlying causes we must first observe how we observe these screens:

• Blink rate can drop up to 60% when focusing on a screen intently. We generally blink once every 10 seconds, which can be decreased to once every 30-40+ seconds in between blinks.  Add a contact lens, which causes corneal paresthesia (loss of feeling) and that rate will decrease even farther.
• The primary purpose of blinking is to brush fresh tears across our cornea. Tears are a 3 part cocktail with 2 parts being nerve innervated and the third relying on blinking! The eyelids themselves are packed full of Meibomian glands that secrete a lipid (fatty) secretion (meibum) that makes up the outer layer of the tear film. While the research is still ongoing there appears to be a link between decreased blinking and Meibomian gland drop out/dysfunction, leading to evaporative dry eye – especially when staring at a screen all day. Add an air-conditioner or heater blowing in your face and that problem can spiral out of control quickly.
• After spending 8 hours staring at a screen we hop right back in our cars to drive home and the quality of our vision is dramatically worse than when we started the day. Why? Because you spend all day disrupting your Tear Film, which fills in all the cracks and crevices between cells on your cornea to give you crystal clear vision. The front of the eye takes on a scab like appearance when dry, starting with a slight stippling pattern all the way to a confluent area of disrupted epithelium. 

Now that we’ve established causation, we can easily solve all this by just blinking more – right? Almost. The second big issue with staring at a near object all day is that our eyes are naturally focused at the distance (if you are so lucky) or you are wearing corrective lenses to focus your eyes at distance. We spend the entire day flexing a muscle in our eyes to see up close and we call that action accommodation. These muscles are autonomic and even if you’ve got the headache of a lifetime from over usage, they are going to fight their hardest to continue to provide you with crisp near vision. Maybe it works and you make it through the day or maybe one of these issues arise – paresis or spasm. They accommodative system can become so tired that it just cramps up and stays in a near focused position, called accommodative spasm, or the system can become so tired that all near vision is just blurred. 

I believe that great treatment starts with understanding. To understand why I recommend what I recommend you must first understand the disease process, as outlined above. I refer to the entire process as computer vision syndrome. Since quitting our jobs and counting dolphins on the beach full time is just out of reach, we work to make doing your job more comfortable, efficient, and less draining by taking some of the strain off your eyes. I often hear patients correlate tired eyes with the overall feeling of tiredness and feeling tired at the end of the day rather than enjoying their post-work time. 

Blinking is the first step, referred to as forced blinking. We often find ourselves staring for long periods and then suddenly blinking and realizing how uncomfortable our eyes feel. Make sure when you are intently focusing that you are also blinking. If you find your blink rate slowing down consider keeping a bottle of oil based artificial tears next to your desk to give your eyes a quick shot of moisture. I recommend the oil based tear to replace the portion of the tear film that is being underutilized due to the decrease in blinking. If you find yourself using the tears more than four times a day, make sure to use a preservative free variety. If you still get dryness, talk to your optometrist about nutritional changes and further treatment to increase Meibomian gland expression. 

There isn’t anything we can do to change the fact that you need to look at a screen all day but we can make glasses that decrease the amount of accommodation, or work,  needed to view that screen. It’s like having a spotter follow you around the gym and do 20-40% of the work for you all day, but only you know they are there doing that work. We call these anti-fatigue lenses, and they have a small amount of plus power built into the bottom portion of the lenses. These are digitally formed lenses with your prescription formed into the physical lens along with the anti-fatigue portion. Some manufacturers offer blue light protection built into the lens material while others offer anti-reflective coatings to decrease blue light penetration. I always recommend anti-reflective coating on computer lenses, beyond the warranty, looking better, and offering blue light protection, they also reduce the backside reflections of the computer reflecting off your eye which can lead to glare and headaches. 

The latest research on blue light has shown that the color or wavelength of the light may be of less importance than they overall brightness of the light itself. Lastly, I always recommend lifestyle changes. Use your devices software to decrease the light output of your computer and phone at night prior to bed. Use dimmed LED lights around the house if you have LED lighting. Make sure you are eating a balanced diet, low in ultra-processed foods and high in leafy greens, omega 3, and beta-carotenes to promote good ocular health.  If you find you live a sedentary lifestyle – increase your physical activity. A lot of research points to blue light affecting circadian rhythm and affecting sleep cycles which I firmly believe in, but I also believe that we’ve become more sedentary and less active overall. Sometimes it takes exerting a bit of extra energy to feel tired a the end of a day. The American Heart Association recommends 30 minutes of elevated heartrate three times a week. Start small and work your way up. Couch to 5k? Join a gym? Walk around the block? The key is STARTING, because anything is more than nothing and the hardest part is just getting off the couch to do it. 

If you are experiencing any of these problems make sure to speak with your doctor and discuss a personalized treatment plan to decrease digital eye strain, increase efficiency, and live your best life. If you have any questions, feel free to reach out as we are always available to our patients. 

Written by our friend: Dr. Jason Klepfisz @ Urban Eye Care PHX