The advent of the digital age has promulgated a scathing image of blue light, for good reason: at night, exposure to blue light from our phones inhibits melatonin release and reduces the quality of sleep. Blue light, however, has also been a key component in jump-starting our circadian rhythm when we wake up and its benefits are often overlooked in light of the media attention around the harms. This article will illustrate what it means, the harms, and ways to prevent it from causing long term damage.
On the electromagnetic spectrum, waves exist from low-frequency radio waves to high energy gamma rays. Right on the border between visible light and UV light exists blue light, the most high energy form of visible light. Its short wavelength causes it to pass right through the retina, penetrating to the cornea.
Some studies suggest a link between exposure to light at night, such as working the night shift, to some types of cancer, diabetes, heart disease, and obesity. However, this linkage is not proof that nighttime light exposure causes these conditions; nor is it clear why it could be bad for us. One thing we do know, though, is that exposure to light suppresses the secretion of melatonin, a hormone that influences circadian rhythms.
However, as mentioned earlier, blue light has also been shown to promote numerous benefits, especially in the morning, serving as one of the major signals of the morning. These include wakefulness, dictating circadian rhythms, alertness, and general cognitive function (find separate source). We experience this every day when we wake up to sunlight, which forces us to wake up whether we want to or not.
Consider, then. Blue light is all around us, and there’s little to be done to avoid it. We, as humans, have made our daily lives one where we stare at it for long periods of time, which can cause damaged retinal cells and age-related macular degeneration. What can we do about it?
Most easily, stop looking at your phone before you sleep. Try to minimize it with other activities that don’t involve direct light, such as reading books. A step further is to buy blue light protection glasses, which specifically block blue light and are useful if you have to stare at a computer screen and often forget to look away and take breaks. Taking the correct steps in managing blue light intake will promote wakefulness, better eyesight, and general health, which is of dire importance.
Works Cited
Choi, K., Shin, C., Kim, T. et al. Awakening effects of blue-enriched morning light exposure on university students’ physiological and subjective responses. Sci Rep 9, 345 (2019). https://doi.org/10.1038/s41598-018-36791-5
Hallows, J. (2012, May). Blue light has a dark side. Retrieved from https://www.health.harvard.edu/staying-healthy/blue-light-has-a-dark-side
Heiting, G. (2020, July 04). How blue light is both bad for you AND good for you! (Huh?). Retrieved from https://www.allaboutvision.com/cvs/blue-light.htm
Holzman D. C. (2010). What's in a color? The unique human health effect of blue light. Environmental health perspectives, 118(1), A22–A27. https://doi.org/10.1289/ehp.118-a22
Comments