Mistakes people often have about blue light and effective eye protection

For a long time, blue light emitted from electronic devices such as smartphones, laptops, televisions . has been accused of causing insomnia, even eye damage. Blue light has a short wavelength, meaning it carries high energy and can damage vision tissue.

Studies done on rats show that prolonged exposure to intense blue light damages their retinal cells. Blue light can penetrate into the retina, which is a collection of cells that convert light signals into nerve signals for the brain, the fundamental mechanism that allows us to see everything.

However, these are results from laboratory research. And the epidemiological studies done on humans tell a different story.

Blue light emanates from electronic devices such as smartphones, laptops, televisions .

As an associate professor at the Optometry School at Ohio State University, Phillip Yuhas has taught and conducted visual studies directly, including working with retinal cells.

"I also directly examine patients who come to the school teaching clinic. Often, patients will ask, how can they keep their eyes healthy while still looking at the screen? computers all day, " Yuhas said.

Patients who want to know if products like blue light blocking glass are often advertised on the internet are effective. But according to Yuhas when it comes to protecting and keeping your eyes healthy, blue light is not the biggest concern you need to be aware of.

Human eye has innate protection

One approach to the topic of blue light and the risk of retinal damage is to consider sunlight. In fact, sunlight is mostly blue light. On a sunny afternoon, sunlight is nearly 100,000 times more intense than your computer screen.

However, very few studies have been done on humans that have found a link between exposure to sunlight and the development of age-related macular degeneration, a retinopathy that leads to loss. Vision is central to the visual field.

If going out on a sunny afternoon doesn't ruin a person's retina, the tablet's dim display in this comparison can't.

So why can blue light damage mouse eyes in animal studies, and not in humans?

If going out on a sunny afternoon didn't ruin a person's retina, the tablet's dim display couldn't.

" That's because the eyes of people differ from those of rodents, " Yuhas explained. Our eyes have innate protective mechanisms, such as the pigment in the macula and the lens itself, that blocks blue light. These structures absorb blue light before it reaches our fragile retina.

But this does not mean that you should remove your sunglasses when you are out in the sun. Because the glasses not only do the task of protecting your eyes from the blue light coming from the sun. Its benefits also come from many other aspects, such as research showing that wearing sunglasses helps slow the development of cataracts.

Blue light and biological clock

" Just because blue light doesn't damage your retina doesn't mean that electronics are completely harmless, or that blue light doesn't affect our eyes , " Yuhas said. "Given its wavelength nature, blue light actually disrupts healthy physiological sleep."

Playing an important role here are blue light-sensitive cells called photosensitive retinal ganglion cells (or ipRGC). These cells are known as the clock knob for the biological clock inside your brain.

ipRGC senses light in the environment to tell the brain about time outside. That means, when you look at a bright screen at night, these cells will reset the clock inside your brain to the time of day.

ipRGC are these cells known as the clock knob for the biological clock inside your brain.

But the key point to note here is that although ipRGC is more sensitive to blue light, they also receive input signals from all other retinal neurons that are sensitive to the entire light spectrum. shining.

Therefore, blocking blue light alone will not improve your sleep. If you want to sleep better, you need to block all types of light at night.

It's the same for people who complain about tired eyes after staring at a computer screen all day long. Blue light is only a pawn to blame.

A recent study demonstrated that blocking blue light alone did not improve the comfort of people working with computers compared to reducing the overall brightness of the screen.

Is eliminating blue light useful?

" Many patients want to know if they should buy some products advertised to block blue light , " Yuhas said. " Based on research, the short answer is" no ".

The truth is that exposure to any kind of strong light too close to bedtime interferes with your natural sleep.

A lot of scientific evidence shows that looking at electronic screens before bed makes it harder for you to sleep than reading paper books. It also robs you of REM sleep, reduces the body's recovery process, reduces the concentration and brain activity the next day.

The problem will be even worse when the phone is pressed too close to the eye.

Blue light blocking glass typically only blocks about 15% of the blue light emitted by a monitor.You can achieve the same effect just by keeping the phone a few centimeters away from your eyes.

In addition, products advertised as being able to block blue light often work ineffectively. For example, blue light blocking glass typically only blocks about 15% of the blue light emitted by a monitor.

You can achieve the same effect just by keeping the phone a few centimeters away from your eyes. Try it now to see if you notice any difference? Is not it?

Yes, a recent meta-analysis study also concluded that glazing with blue light-blocking coatings did not significantly affect sleep quality, comfort when looking at a computer screen, or health of the retina.

These methods give real effectiveness

There are many ways to make you more comfortable looking at screens and ensuring the quality of sleep.

The first is a good rule of thumb: turn off all your electronics before going to bed. The American Academy of Pediatrics recommends that children's bedrooms be an area without electronic screens, but all of us adults should follow this advice.

Outside the bedroom, when you're forced to look at a monitor, lower its brightness.

If you experience eye strain when working with a computer, make sure you wear your glasses properly. Please see an eye doctor for the most accurate advice on this issue.

Then you need careful eye care. For example, when looking at a computer screen, you not only look at it but also stare, even straining your eyes without blinking. Under normal conditions, we blink about 12 times per minute. But when working with computers, the number dropped to half.

As a result, tears outside the cornea evaporate can cause inflammation on the eye surface. That's why you get dry and tired eyes after a day at the computer.

For example, when looking at a computer screen, you not only look at it but also stare, even straining your eyes without blinking.

"I often advise my patients to take two steps to make sure their eyes are moisturized, " Yuhas said.

" Step one, follow the 20-20-20 rule . The American Vision Association defines this rule as a 20-second break every 20 minutes to look at an object at a distance of 20 feet (6 meters). This will allow you to blink and relax. "

Even on your phone, there are many apps that help you set a timer and remind you to do this.

" Step two, use eye drops if you intend to work with the computer for a long time. This tactic will support natural tears and keep your eye surface well-hydrated," Yuhas said. recommendation.

" But avoid eye drops that claim to eliminate redness in your eyes. They contain long-lasting red eye medicines and preservatives that can damage the outer layers of the eye."

Accordingly, artificial tears labeled " no preservatives" are usually the best option.

In the end, Yuhas said, based on his experience, people should not believe in the hyper-hype information about the impact of blue light, so they do not waste money on buying useless products.

Instead, the simple, effective method anyone can do is to evacuate all devices with screens out of the bedroom, reduce the brightness of external devices, and keep your eyes moist. . And don't forget to blink!

1. Why is blue light from phones harmful to eyes?
2. What is blue light? How is blue light harmful to the body?