Does blue light have a dark side?

Blue light is not a new phenomenon. As well as coming from our phones, there are also high levels of blue light emitted from televisions, for instance.

Blue light is everywhere

The sun is the most significant contributor to blue light. Vibrating within the 380- to 500-nanometer range, blue light has the shortest wavelength and highest energy. Blue light contributes to about a third of the light around us.

It has benefits, like keeping us awake in the day

Blue light is not a term given just for light emitted from the screen. It’s a natural light that is also there in the daytime, helping our attention and reaction times.

Blue skies

High-energy blue light rays scatter a lot easier and faster than other light rays on water and air molecules. This is what makes the sky blue.

Functional use

Blue light is used tactically in places where people need to stay awake for long hours. For example, hospitals are lit with fluorescent and LED lighting, which emit blue light.

The human eye can’t block it out

While the cornea and lens of the human eye can block around 99% of UV light to the retina, virtually all blue light gets through.

When it becomes problematic

However, when the sun goes down and the light turns to darkness, we shouldn’t naturally be seeing it, which is where the problem starts.

The main reason for bad sleep

Light at night is one of the main reasons people don’t sleep well, increasing the risk of depression, diabetes, and cardiovascular problems. It also affects our health in other ways.

The body clock

Daylight, which is made up of blue light, keeps our circadian rhythms in balance. These are the physical, mental, and behavioral changes that happen according to light. These processes are also relevant to most plants and animals.

Melatonin, the sleepy hormone

The reason for this is because light affects melatonin, a hormone responsible for sleeping rhythms.

Altered circadian rhythms and health

Harvard University did a study that changed subjects’ circadian rhythms. Their blood sugar levels increased, throwing them into a prediabetic state. Also, their levels of leptin, a hormone that leaves people feeling full after a meal, went down.

It suppresses melatonin

Harvard found exposure to blue light compared to exposure to green light (literally green light–think of a green lightbulb) for six and a half hours suppressed melatonin twice as much and for twice as long (1.5 vs. 3 hours).

Glasses and goggles

The study suggests that shift workers and night owls should protect themselves from blue light with some kind of goggles or glasses.

Consider different light for your bedroom

There are other ways to protect yourself from this blue light at night, like using dim red lights for night lights. Red light is less likely to shift circadian rhythm and suppress melatonin.

Put the device away, or get a filter

Avoiding looking at screens is best at night. But if this isn’t possible, some programs cut out the blue light on your screen during bedtime hours (which you set personally). One of these programs is Flux.

“Visual noise”

Too much blue light isn’t good for our brains. It has been described as “visual noise.” It can also cause eye strain, headaches, blurred vision, and neck and shoulder pain.

Work computers

According to Dr. Howard Murad of Murad Skincare, spending four eight-hour workdays in front of a computer exposes you to the same amount of energy as 20 minutes in the midday sun.

DNA and blue light

Furthermore, the penetration of blue light through the skin causes reactive oxygen species, which leads to DNA damage and a breakdown of collagen and elastic fibers.

The evidence for skin damage is limited

However, studies on blue light’s effect on the skin are lacking. One study suggested that people with darker skin who exposed their skin to a lot of blue light experienced more swelling, redness, and pigment changes than people with lighter skin who were exposed to similar levels of UV rays.

Who’s responsible?

The big question is whether manufacturers of products are responsible for the harm that their products are doing to people. The answer to this is complicated. But one thing is for sure: there will not be heavy regulation on how much blue light phones can emit anytime soon.

Freedom of choice

For example, when people travel between time zones or need to use their devices when other people are sleeping, they shouldn’t have to look at their device with blue light filtered out.

It’s the only way

Blue light is necessary to see images’ colors. It isn’t an ideal solution to have our devices manufactured to limit the amount it emits at night. It’s not practical.

Blue light filtering

For example, when looking at your device with one of these blue light filters, an image of a blue sky would not be blue. If you’re watching a movie, the coloring is completely off.

Big tech

On the other hand, it bodes well for big tech companies and pretty much any business that profits off of people consuming content. The blue light on our laptop screen is what keeps people awake and watching more YouTube clips, Netflix, and reading articles. But just because they profit doesn’t mean they’re doing something sinister.

Responsible consumption of media

Since there’s no obvious solution, the responsibility is on the user for now. Like with many products available in the market, there is a potential for them to be dangerous, so it’s up to the consumer to find out how using a product can be hazardous and avoid using it that way.

The bottom line

Blue light is not going to significantly harm anyone’s eyes long term. It cannot be presumed that it is damaging people’s skin significantly either. The evidence for blue light skin damage is weak. Any evidence that exists does not suggest it causing severe damage.

Long hours is dangerous in indirect ways

However true, spending long hours on devices is still dangerous. Not only does it mess with your biological clock, but it also has been linked to health and social issues.Long hours on devices

Long hours on devices

These real issues associated with blue light are secondary and are a result of spending a lot of hours on devices. These problems include neck pain, strained relationships, obesity, depression, and anxiety.

Sources: (Harvard Health Publishing) (All About Vision) (Harvard Health Publishing) (Allure) (UC Davis Health) (Raconteur) (The New York Times) (Journal of Investigative Dermatology)

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