Do I Need Blue Light Glasses?
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Staring at a screen is hard on the eyes. Prolonged use of computers and tablets can cause digital eye strain, which can result in everything from itchy, dry eyes to headaches and blurry vision. These symptoms are almost always temporary, but they aren't very much fun, either.
Digital eye strain can be caused by any number of factors, and one of them is blue light. Blue light is very common in computer and digital device screens, and there's some evidence that too much blue light can cause eye and sleep problems.
Enter blue light glasses. These glasses claim to block blue light, in theory reducing any harmful effect the light might cause. You’ve probably seen a blue light glasses advertisement and thought “do I need a pair?”. The answer is complicated. Let’s dive in.
The History of Blue Light
When we talk about "blue light," we're talking about a certain part of the visible spectrum. The visible spectrum is the part of the electromagnetic spectrum that is visible to the human eye. Every visible color of light is on this spectrum, with "blue light" referring to the high energy light within the blue band of that spectrum.
Until fairly recently, technology was not able to create blue light efficiently. That changed in 1993, when Shuji Nakamura, an electronics engineer at Nichia Corporation, and professors Isamu Akasaki and Hiroshi Amano of Nagoya University developed the technology behind blue light emitting diodes (LEDs). All three men were awarded the Nobel Prize in Physics for their work, and the LEDs they pioneered are the main source of blue light in the technology we use today.
What are Blue Light Glasses and What Do They Do?
Blue light glasses are very similar to sunglasses. Sunglasses block the UV rays of the sun, while blue light glasses block blue light, with a particular focus on narrow-spectrum blue light.
The visible spectrum is measured in wavelengths. Blue light has a wavelength between 400 and 525 nanometers (nm). The blue light that blue light glasses are designed to protect against is narrow-spectrum blue light. This high energy light has a wavelength of 400 to 450 nm, and it's commonly produced by LEDs.
Blue light glasses have a coating on their lenses that reflects blue light. It’s important to note that blue light glasses do not cancel out every bit of blue light you might be exposed to. They reflect somewhere between eight and ten percent of blue light. Your eyes will absorb less blue light than they would without the glasses, but you’re still going to be exposed to a lot of blue light.
Do Blue Light Glasses Work
Blue light glasses work in the most basic sense: they filter out some amount of blue light. But it’s unclear if blocking blue light offers any eye-health benefits.
Digital eye strain is caused by prolonged use of a digital device. Digital devices emit a ton of blue light, but there’s no clear evidence that blue light contributes to digital eye strain. A study by the SUNY College of Optometry found that subjects using a tablet with a filter that blocked 99% of blue light saw no reduction in eye strain compared to subjects with no filter at all.
There is evidence that blue light can disrupt sleep, especially if you’re using a device right before bed. According to a study from France’s Agency for Food, Environmental and Occupational Health & Safety, it’s unclear if wearing blue light glasses helps reduce blue light-related sleep problems.
Blue Light’s Effect on Sleep
Like we said above, blue light exposure absolutely can have an adverse effect on sleep. Exposure to any light suppresses melatonin, a hormone your body produces that influences your sleep-wake cycle. This is why it's much harder to fall asleep with the lights on.
The issue with blue light is that it is very good at suppressing melatonin. A Harvard study found that blue light suppressed twice as much melatonin as a comparable source of green light. In theory, blue light glasses and filters will reduce blue light’s melatonin suppression. But, as indicated in the French study, we simply don’t know how much that helps.
Other Ways to Reduce Eye Strain
While blue light glasses are not an effective way to reduce digital eye strain, that doesn't mean that reducing it is impossible. The simplest way would be to reduce your screen time, but that's a tough ask for many people.
If you're going to be using a computer for a long period of time, there are some easy things you can do that can help with eye strain. Give your eyes a break from the screen every so often. These breaks can be as short as 20 seconds or as long as 15 minutes or more. Try to reduce glare and make sure your room is bright enough: you don't want your computer screen to be the brightest thing in the room. If you find that computer use gives you dry eyes, make sure you have a dropper of artificial tears to refresh your eyes. You can also make changes on your device, such as lowering the brightness or increasing the text size.
These methods can help reduce eye strain, but none of them are going to completely eliminate it. Using a computer or smartphone is hard on the eyes, there's no real way around it. Still, it's worth giving some of these techniques a try. They might make your day a little easier on the eyes.
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