- Carolyn Mish
Does Blue Light Exposure Harm Your Health?
Updated: Oct 3, 2020
By: Carolyn Mish, Contributing Writer
In the age of COVID-19, social media, and Zoom meetings, humans are spending more time in front of screens than ever before. Could the overexposure to blue light present in phones and computers be harming our bodies in more ways than we expect, or is the panic a myth created to sell tinted glasses?
Blue light is a necessary part of the light spectrum, and everyone is exposed to it in their daily lives. But it can impact you in more ways than you would expect.
Blue Light and Sleep:
Blue light has a shorter wavelength than other types of light, making it higher in energy and more potent. During the day, natural lighting is primarily made up of blue light. This helps to regulate the body’s circadian rhythm, which is the body’s 24-hour sleep-wake cycle. Blue light is necessary to have a normal circadian rhythm, by triggering the production of cortisol in the brain. Cortisol is a hormone produced in the hypothalamus that promotes feelings of alertness and helps you feel awake, and in turn, suppresses the production of sleep hormones. As daylight naturally fades and the amount of blue light we receive decreases, cortisol production slows and the brain starts creating melatonin. Melatonin is the primary chemical that makes us feel fatigued and ready for sleep. This push and pull is the circadian rhythm at work: and a multitude of factors can throw the sleep-wake cycle out of whack.
Just as exposure to blue light can promote a healthy sleep cycle, an excess amount of it can disrupt the body’s circadian rhythm. Exposure to blue light suppresses the production of melatonin for twice as long as exposure to green light does. This delay in the sleep cycle means that you get less R.E.M (rapid eye movement) sleep and will wake up feeling less rested.
Reducing your exposure to blue light for the three hours before you plan to go to bed can help reduce the effect that blue light has on your circadian rhythm. On most mobile devices and computers, there are settings to automatically switch your screen’s tint to a warm shade, which can also help if you have to be on screens during nighttime.
Blue Light and your Eyes:
Blue light enters your body through your eyes: first, passing through the cornea and lens, and then your retina. Overexposure to light from the sun, such as UV rays, has been proven to be harmful in the long term, with connections to cataracts and age-related macular degeneration (conditions that harm your eyes). The amounts of blue light emitted from computers and other screens are minimal in comparison to that emitted from the sun.
Due to the modernity of widespread screen usage, the effects of blue light and their connection to eye issues are still being researched. However, how we use our computers can cause a phenomenon known as digital eye strain. The eyes may feel fatigued and sore, and you may develop headaches as a result of poor computer habits.
The American Academy of Ophthalmology claims that the excessive time spent in front of screens, and the changes observed in blinking while using them is to blame for eye strain, not the blue light itself. They recommend using artificial tears if the eyes feel dry, sitting at least an arm’s length away from the screen, and obeying the 20-20-20 rule. Every 20 minutes, look at something 20 feet away and focus on it for 20 seconds. This will help give your eyes a break.
Blue Light Glasses:
With the surge in reports of digital eye strain, a new industry has popped up to meet the demands of those suffering from it. Hundreds of companies now offer blue light blocking glasses, with technology claiming to block the light from entering your eyes and to minimize symptoms of eye strain. This technology usually includes a subtle orange tint, which complies with basic color theory: orange will cancel out the blue. The American Academy of Ophthalmology does not recommend these glasses for people suffering from eye strain: they simply urge you to change your digital habits.
If you find yourself dealing with sore, dry eyes, or waking up tired after a night spent scrolling on your phone, implement subtle changes to the ways in which you use your screens to help you feel better. If you are still dealing with eye strain after minimizing your screen usage and developing better habits, see an ophthalmologist for further assistance.