For many Americans, evenings are a time for winding down. We like to bundle up in front of the TV and binge our favorite Netflix show or catch up on the ever-evolving Facebook and Instagram feeds before getting some much-needed shuteye. But what if the evening screen-time is actually less relaxing than we thought?
However, exposure to blue light on its own is not a bad thing. It’s one of the primary ways our body regulates our circadian rhythm, also known as the body’s natural biological clock. A well-functioning circadian rhythm is important for good mental health, a healthy sleep schedule, and better cognitive function.
During the day, we receive most of our blue light exposure from the sun. This exposure tells our body to be awake, alert, and energetic. At night, our bodies naturally produce a hormone called melatonin as a reaction to decreased exposure to blue light. This hormone is responsible for that sleepy feeling you get after a long day and is secreted as a natural reaction to darkness. This hormone is also an incredibly important part of the sleep cycle.
The problems occur when our bodies are not able to produce melatonin at night due to nighttime exposure to blue light through smartphones, tablets, TV, or even particularly bright LED light bulbs. Studies show that being exposed to blue light up to four hours before bedtime can affect melatonin levels and sleep quality and that there are links between suppressed melatonin levels and increased risk for metabolic syndrome, depression, cancer, and obesity.
Thankfully, reducing our risk of melatonin suppression is easy. The most obvious way is to limit screen time to two to three hours before bedtime. Perhaps crack open a good book and read by candlelight or warm-colored lamp to curb exposure to the bright white LED lights that are common in households nowadays.
However, if you’re not willing to completely abandon your evening routine of Netflix, Instagram, and email, there are a few ways around it. Invest in a pair of blue-light-blocking lenses. Research in these lenses shows that using blue-light-blocking lenses stimulates the production of melatonin in levels similar to those produced in darkness. In addition, there are computer programs like f.lux that filter the blue and green light from computer screens so you can burn the midnight oil without disrupting your sleep schedule (the Night Shift program pre-programmed on iPhone does the same thing). Finally, make sure that during the day you are exposing yourself to plenty of blue light. Our circadian rhythm is just as dependent on lots of blue light during the day as it is on darkness during the evening.
While it doesn’t seem like much blue light exposure is an important part of our daily life, all it takes is one small intentional change to make a lasting difference in the way we feel every day.