You might have heard things about how “blue light” is bad for you, but exactly what kind of blue light? After all, the sky is blue, and blue is often a color we find soothing and pleasant. By blue light in this context, we mean exposure to sources of blue light, particularly at night. Because blue light is a color our brains associate with the sky and broad daylight, too much blue light at night tricks our bodies into thinking it’s still daylight. Our modern lives greatly increase our exposure to blue light from artificial sources, whilst often keeping us indoors and away from the sun during the day.
What Are the Sources of Blue Light?
There are two main sources of blue light. The first is screens and electronic devices. This includes modern televisions as well as computer monitors and mobile devices. The other is modern, energy-efficient light bulbs. Incandescent light bulbs tend to produce more yellow light, while LED and fluorescent bulbs are bluer. There are also some minor sources. For example, the USB multi chargers sometimes called “octopi” that a lot of people travel with often have a blue light to indicate that they are active. Nightlights can also be a blue light source, especially as people tend to see blue light as calming and thus choose blue nightlights, especially for young children.
Why is Blue Light Bad For Us?
The primary reason why blue light late at night is bad for us is that it can mess up our circadian rhythm. Our internal clock is aligned by daylight, so having too much blue light late at night can trigger insomnia, particularly in people who tend to already be night owls. Blue light at night suppresses the natural production of melatonin that tells us when we need to sleep.
There are also some indicators that blue light can increase the risk of macular degeneration and cataracts and contribute to eye strain, especially amongst people who spend a lot of time looking at a screen. Blue light tends to scatter more and is harder for your eyes to focus, meaning that they have to do more work. There are some links with cancer, diabetes, heart disease, and obesity, but these may be side effects of the primary problem, which is blue light messing up our sleep.
Blue light is not always bad for us. In fact, exposure to blue light during the day improves mood and alertness. Exposure to daylight is the best, so it is always a good idea to go outside every day, if only briefly. Ideally, you should go outside first thing in the morning, as this will “wake up” your brain and body and help prevent something called sleep inertia, where you are only part of the way awake.
What Can We Do About Blue Light?
First of all, you should not avoid all sources of blue light at all times. In some cases, your doctor may even prescribe blue light exposure, for example, to treat Seasonal Affective Disorder. The largest source of blue light is the sun, and exposing yourself to the sun (taking care to protect yourself from excessive UV) is generally a good thing.
However, we also need to do something about the amount of blue light exposure we get at certain times and in certain contexts. Here are some things you can do:
Stop using electronic devices two to three hours before bed, if this is practical. This includes watching television. Instead, read an old fashioned paper book or play physical games. Electronic paper e-readers are a better choice than tablets.
If not using your screens is not practical, then use a “night shift” app or setting. This shifts the spectrum of light emitted by your device to more yellow at a certain time. Set it to somewhere between two and three hours before bed. Some of these apps use geolocation and sunset time to adjust automatically. Note that even a few minutes spent away from your screen before lying down to sleep can help.
Buy LED and fluorescent bulbs that have a more yellow light profile, achieved by coloring the outside of the bulb, especially for task lighting. Or purchase a lamp with a yellow or red shade.
If you or your child uses a nightlight, or if you have nightlights in the bathroom (A good idea, as turning on lights at full brightness can make it hard to get to sleep) choose yellow or red lights over blue. Red or yellow nightlights have been demonstrably proven to improve sleep over blue or white light, and red nightlights seem to be particularly soothing to babies.
If you have an electronic device with a blue light in your bedroom, put it behind something or cover it. This can be a particular issue in hotels. Choose an alarm clock with, ideally, red numbers rather than green, white, or worst of all…blue. Backlight alarm clocks that have a soft yellowish-grey screen are also good, but not ones with a blue screen.
Get a blue light filter for your phone or tablet. Get one which is made of tempered glass and it will also have the beneficial effect of protecting your screen from scratching. You can also get these filters for computer screens. They often also reduce glare, and thus eye strain. If you work on a laptop in public and want a privacy screen, get one which also filters blue light.
Avoid having your phone in your bedroom. If you have to (for example if you live in a studio, are staying at a hotel, or need your phone’s alarm) then put it in a case with a flap or put it on the nightstand upside down so as to reduce light exposure if it turns itself on. If you don’t need the alarm, you can also shut your phone down. The same goes for tablets or e-readers.
Expose yourself to plenty of blue light early in the day when your brain is expecting it, such as through a morning walk or, weather permitting, eating breakfast or lunch outside. This is particularly important if your office or cubicle does not have a window. We are naturally meant to be outdoors during the day.
Invest in a pair of blue light lenses. You don’t need a prescription unless you already have prescription eyewear. These are a particularly effective way of protecting yourself as they block all sources of blue light, not just the screen you added a filter to. However, they will not protect you from blue light creeping into the room while you are trying to sleep, and you should take other precautions to protect yourself.
Why Are Blue Light Lenses the Best Solution?
The best solution to blue light exposure, especially for people who work at a computer and then like to play video games or watch television is blue light glasses. These filter out all of the blue light from reaching your eyes.
If you do not need prescription glasses, you can get blue light-blocking lenses and frames from an eye doctor in much the same way that you can get sunglasses. However, they tend to be a bit more expensive – you are probably looking at about $80 for the lenses, plus your choice of frames. The improvement in your sleep patterns, however, is more than worth it. Very cheap blue-light-blocking glasses have an amber or reddish tint to the lens which can look dorky, but you can get more expensive ones which look just the same as normal eyeglasses and are more effective. The amber “goggles” tend to block a bit too much blue light. You can wear them at all times when using a computer, or only at night.
If you do need and use prescription eyewear, you can talk to your eye doctor about adding blue light blocking to your glasses. Blue light blocking can be added to most types of glasses, but what you should ask for is a prescription set to your typical computer reading distance. This improves eye strain over using either readers or distance glasses to use a computer (using bifocals or varifocals is often a bad idea as the narrow channel can compromise your ergonomics and cause back and neck problems). Generally, you should also get an anti-glare coating on computer glasses. While this can increase the expense, it can help improve your health and even your productivity.
By adding blue light protection to your computer glasses, you can protect yourself from all of the negative effects of blue light late at night. You might also look into blue light distance glasses if you work a night shift or have to drive home from work late at night, or even if you are addicted to late night TV binge-watching. At Eye Consultants of Atlanta, we use Blutech blue light blocking glasses. Contact us if you are a heavy computer user and want to learn more about how blocking blue light with glasses can improve your sleep and overall health.