You may have heard about something called blue light. And you may have even heard that it’s bad for you.

So, What is Blue Light?

Well, blue is just one color on the visible light spectrum (just like red, orange, yellow, green, indigo, and violet.)

FUN FACT: It’s actually the reason the sky appears blue! In this case shorter, smaller wavelengths collide with the air molecules and scatter creating a blue illusion (red light, at the opposite end of the spectrum, has much longer wavelengths.)1

So, where is blue light found?

Once upon a time we only found blue light in sunlight. But today, it’s found widely in electronic devices – TVs, computers, laptops, smartphones, and tablets. Basically, anything powered by LED.2

blue light | sight origins

Why Is Blue Light Bad for You?

Now, blue light is not innately “bad.” But it can be disruptive or detrimental to eye health when your eyes are exposed to it for too many hours. Your eyes are really good at blocking some types of light, like UV light, but they’re not so great at blocking the blue spectrum of light. So it passes through to the retina at the back of the eyes very easily.3

Here are two of the biggest reasons blue light can be harmful:

1. It Can Disrupt Your Sleep

Blue light suppresses melatonin, the hormone responsible for preparing us for sleep at the end of each day. Melatonin is released by the body a few hours before your regular bedtime (of which your “body clock” has established). Its goal is to reduce alertness, and wind the body down so that it can better obtain a sleep state. So reading or watching something on your laptop or smartphone in the few hours leading up to bed (especially in bed!) is not going to help you fall asleep easier. It’s actually working against you. This is even worse for children and teens whose eyes appear to have a much greater sensitivity to blue light.4

Continually disrupted sleep can affect mood, metabolism, blood sugar, and the heart – not to mention basic coordination. In fact, sleep deprivation has been compared to alcohol intoxication in terms of its effect on the brain.5

2. It May Contribute To Retinal Damage

Some recent studies have found that excessive blue light in the retina may lead to damage, cataracts, and even macular degeneration. Macular degeneration is the leading cause of permanent vision loss in people aged 50 and over.6

One study by The Schepens Eye Institute showed that blue light may indeed be a risk factor for macular degeneration due to damaging the part of the eye known as the macular pigment.7

blue light | sight originsMeanwhile, a study out of the University of Toledo determined that blue light exposure may trigger a toxic chemical reaction in the eyes that kills photoreceptor cells – also leading to Macular Degeneration. It’s important to note that the Toledo researchers also found what they believe to be the reason we all don’t just go blind from this shade of light. That reason is the antioxidant alpha-tocopherol (a type of vitamin E) which considerably reduces damage from blue light. But vitamin E levels drop considerably with age so that protection becomes weaker and weaker.8

Can Blue Light Also Be of Benefit?

Yes! As you’ve seen blue light is a completely natural part of sunlight and it certainly can also be a beneficial thing.

Blue light …

1. Can kill the bacteria Propionibacterium acnes (P. acnes) which causes skin blemishes. One clinical trial found that it reduced blemishes by 64%.9

2. It may be the best kind of light for treating mood disorders, such as seasonal affective disorder (SAD) as it can penetrate the retina easier than white light.10,11

3. May help fight fatigue and daytime sleepiness.12

4. May help to regulate sleep disorders, especially for those who live or work in zones with compromised sunlight.13

Final Thoughts on Blue Light

The bottom line with blue light is that it’s all about how you use it. We’re taught in life that a healthy life is one lived in moderation. Well, the same goes for blue light. You can’t escape it, it’s in your sunlight. But you can certainly minimize your face time with it.

The big concern with today is that we use so many devices all day, every day. And more often than not, you’re using them at close range, for extensive periods, and right before bed.

blue light | sight originsBut with modern concerns about extensive exposure to blue light, it’s also become a lot easier to practice good eye health and protect your eyes. There are now many apps available, as well as physical glasses, that will help to block blue light on your devices. These often give the screen an orange-ish tone instead.

But that’s not a free pass to go back to scrolling social media in bed. It’s still a well-studied fact that this kind of brain stimulation right before bed can also play havoc with your sleep – with or without that blue glow.4

Learn More:
What Are Eye Floaters and How to Protect Your Eyes
These Are the Telltale Signs You Need Glasses
What is Hyperopia: How to Tell if You’re Farsighted

Sources
1.https://spaceplace.nasa.gov/blue-sky/en
2.https://sleepfoundation.org/sleep-topics/why-electronics-may-stimulate-you-bed
3.https://opto.ca/health-library/blue-light-is-there-risk-of-harm
4.https://www.washingtonpost.com/national/health-science/blue-light-from-electronics-disturbs-sleep-especially-for-teenagers/2014/08/29/3edd2726-27a7-11e4-958c-268a320a60ce_story.html?utm_term=.993a9d695a2b
5.http://journals.sagepub.com/doi/abs/10.1177/1545968313508472
6.https://nei.nih.gov/health/maculardegen/armd_facts
7.https://www.macular.org/ultra-violet-and-blue-light
8.http://utnews.utoledo.edu/index.php/08_08_2018/ut-chemists-discover-how-blue-light-speeds-blindness
9.https://www.ncbi.nlm.nih.gov/pubmed/12413768
10.https://www.ncbi.nlm.nih.gov/pubmed/19016463
11.https://www.health.harvard.edu/blog/seasonal-affective-disorder-bring-on-the-light-201212215663
12.http://journals.sagepub.com/doi/abs/10.1177/1545968313508472
13.https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0102827
14.http://time.com/4565122/smartphone-screen-time-sleep/