The advent of artificial light has given us a way to have light without relying on the sun. We use this light to our convenience when we spend the later hours of our day inside our homes with artificial light from electronic devices. As the sunlight fades, the body starts to change to a night-time mentality, where melatonin levels increase, body temperature decreases, sleepiness increases, and appetite disappears. Even if we don’t sleep, the time spent in this relaxing state is rehabilitative. However, our modern world brings trouble. We are bathed by lights that have the same strong wavelength as the light we wake up to. As a result, our transition to night mentality has been postponed by hours. Using computers, phones, and other electronic devices exposes us to varying levels of light. One of these is blue light, which can have a range of effects on us.
Overview and Effects
The spectrum of visible light contains many different colors of light, varying from red, orange, green, blue, indigo, and violet. Rays at the red end of the visible light spectrum have longer wavelengths and thus less energy. In contrast, rays at the violet end of the visible light spectrum have smaller wavelengths and more energy. Blue light rays that have the shortest wavelengths are sometimes referred to as blue-violet or violet light. Blue wavelengths are helpful during daytime hours because they stimulate concentration, response times, and mood. However, these same things are also stimulated at night, which is not beneficial. Namely, increased exposure to blue light from electronics and lighting at night can change sleep patterns.
Your sleeping pattern is determined by your circadian rhythm, which is the 24-hour cycle of sleeping and waking. The length and time of this cycle determine many bodily functions. Everyone’s circadian rhythm is unique, but a few common trends are present. These are mainly the points that your body is optimized to throughout a 24-hour period. Light exposure, including blue light exposure, stimulates hormones that keep us active and awake throughout the day. When blue light is released at night, it blocks the release of melatonin, a sleep hormone that makes us tired. Disruptions in the circadian rhythm of your body can give rise to an array of sleeping issues. Overall, there are many negative consequences of a disrupted circadian rhythm.
Exposure to light suppresses the release of melatonin, a hormone that causes you to feel sleepy. Even dim light can interfere with the circadian rhythm and melatonin secretion of an individual. A mere eight lux, a level of visibility surpassed by most table lamps and about twice that of night lights, can have negative effects. New studies show that exposure to blue light over long periods can lead to damaged eye cells. Light at night is part of the reason why so many people don’t get enough sleep. Even though the blue light you receive from a device pales in comparison to that from the sun, your devices are much closer to your eyes. There are some ways to reduce the negative effects of blue light. Beyond the 7 to 8 hours of sleep you’re trying to get every night, you can attempt to get three more hours of relative darkness. After dinner is a smart time to dim the lamps and avoid the bright blue screens. Further, you can replace lamps in your bedroom and bathroom with dimmer, longer-wavelength lights, start using blackout curtains to block the street lights that shine through your windows, and use an eye mask when it’s time to go to sleep.
Blue light is still necessary for us. It helps with our health by improving alertness, cognitive function, and brain health. The problem is that we are now interacting with unnatural levels of blue light, which can lead to health problems. One way to protect yourself is to use low red lighting for night lights because red light is less likely to change the circadian rhythm and to inhibit melatonin. You should also try and limit your screen time before you sleep and avoid looking at bright screens around two hours before bedtime. There are also many apps available that block blue light, such as the night shift setting. Your eyes are one of the most important sense organs, so taking care of them is vital and necessary.
Harshal Chinthala, Youth Medical Journal 2020
“Blue Light Has a Dark Side.” Harvard Health Publishing, Harvard University, May 2012, http://www.health.harvard.edu/staying-healthy/blue-light-has-a-dark-side.
Heiting, Gary. “Blue Light Facts: How Blue Light Affects Your Eyes.” All About Vision, AAV Media, LLC, Aug. 2020, http://www.allaboutvision.com/cvs/blue-light.htm.
“What Is Circadian Rhythm?” Sleep Foundation, OneCare Media, 25 Nov. 2020, http://www.sleepfoundation.org/circadian-rhythm.