Perhaps many people have seen a blue light blocking function while using electronic devices. Also, blue light blocking glasses are not difficult to find around these days. Blue light is a blue line of light existing between 380-500nm of wavelengths that is emitted from monitors, smartphones, and televisions. It is known that long exposure to blue light can add to eye fatigue, causing dry eye, and in severe cases, damage to the retina or lens. Especially on nights when there is relatively little light, the iris becomes larger and a large amount of light reaches the retina, which can cause more serious damage if exposed to blue light.

Blue Light: Damaging to Your Eye Health

Following these social conventions, many experiments were conducted to prove that blue light is medically dangerous. Hara Hideoaki, a professor at Japan’s College of Pharmacy at Gifu University, examined how the blue, white, and green tricolor lights from LED lights affected the visual cells of mice for six hours each. Experiments have confirmed that 80 percent of cells flashed by blue light are damaged. Unlike green light, which causes little change in visual cells, the level of free radicals that progresses aging also tripled with blue light.

The photo shows the mouse’s visual cells observed after six hours of blue, white, and green LED diodes in the mouse’s eyes. Control is what it looked like before the experiment.

In October last year, a female student in Taiwan became color blind due to prolonged exposure to blue light. After using her smartphone for more than 10 hours every day during the summer vacation, she was almost injured because she couldn’t distinguish colors of the traffic light when crossing the crosswalk. Visiting a nearby hospital, she was the first in the world to be diagnosed with acquired red-green color blindness and cancer compliance decline caused by exposure to the blue light caused by long-term smartphone use. The doctor explained that exposure to blue light with high energy for a long time affected the cones of the retina, and that active oxygen produced near the retinal cells attacked and wounded the cells.

If blue light is dangerous, why do you look at the sky?

According to recent studies, a new argument has been raised that blue light’s damage has been exaggerated. Although it is not known exactly how blue light works on the eyes, it was hastily decided that the cause was blue light. Those who stick to this position mainly point out the effectiveness of blue light blocking lenses. According to the Cochrane review released in 2018, blue light blocking lenses had no effect on vision and had no effect on the occurrence of eye disease such as macular degeneration. According to their experiments, blue light blocking lenses did not cause any harm, but they also didn’t affect eye health, eye fatigue, or sleep. According to a blue light harmfulness paper on computers and tablets published in the 2016 Cambridge Eye Science Symposium in Nature, no mobile display device under extreme long-term observation conditions has presented a cause for public health concerns. The official position of the American Academy of Ophthalmology also argued that there was no scientific evidence that the blue light of digital devices could cause eye damage or eye fatigue. Rather, they pointed out that the level of blue light emitted by displays is extremely small compared to the level of blue light emitted by natural light viewed through the sky, making it more dangerous to see the blue sky, according to the stance that blue light is harmful, which is untrue, arguing that there are no scientific persuasions in the preceding studies.

As the debate over how blue light affects the eyes continues, it is necessary to be aware of blue light, but leave open to the possibility of excessive marketing and pay attention to the follow-up studies. Although, we should be aware that both of the positions – blue light is harmful and it is not harmful – maintain prolonged use of electronic devices adds to eye fatigue. Don’t forget you need proper rest when you use electronic devices for a long time.

Chung Yeongyu  ygchung00@naver.com

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