Blue Light: Is it Really Good for your Eyes?
The more that we have collectively turned toward the daily use of digital devices, the more we have heard about vision problems in people of all ages. Energy efficiency, digital use, and our basic lifestyle habits routinely put us in direct contact with blue light. In recent years, there has been quite a bit of media attention placed on this chronic exposure to blue light. So much so, that the term “good blue light” has become increasingly common. This is an important detail that deserves its discussion.
A Look at Blue Light
Light occurs across a spectrum of wavelengths. The natural human visual system can process wavelengths in the range of 400-750 nanometers. Blue light falls in the 400-500 range on this spectrum. Interestingly enough, these cooler colors of light have higher energy output. This means it is advantageous to investigate the effects that various wavelengths have on health and wellness. In particular, how light affects the eyes.
What’s Good and What’s Bad?
Eye strain is often linked to the use of digital devices. These devices often have the blue light that is below 430 nanometers. According to research, blue light that is less than 460 nanometers presents a risk of oxidative retinal damage. The effects of blue light are cumulative, meaning that the more exposure that occurs over time, the more damage adds up. This damage could result in a serious eye condition, such as age-related macular degeneration. Because of this link, lower wavelengths of blue light have become notoriously “bad.”
In the good old days, before alarm clocks and 9 to 5 jobs, the body was allowed a natural sleep rhythm. The change in natural light at nightfall would prompt the production of melatonin, a sleep hormone. At sunrise, the bright light of morning would halt the production of this hormone, making us feel awake and energetic. Because this natural process involves blue light higher than 460 nanometers, wavelengths above that range have been called “good.”
The Bottom Line
The full range of blue light, which is present in digital devices, is 400-500. That means some wavelengths are generally “good,” while others will stand in the way of melatonin production. Perhaps you have noticed that, if you work on the computer too late at night, you cannot sleep until well past midnight. That’s the workings of shorter wavelengths of blue light. Children are also susceptible to the hazards of blue light from electronic devices, increasing the risk of poor academic performance and behavioral issues stemming from a lack of sleep.
Blue light is still under heavy investigation by researchers. During the daytime hours, higher wavelengths of 460-500 are beneficial, but not after a certain time. Ultimately, “good blue light” seems to be more a matter of timing that wavelength.
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