Early man evolved to see within the visible light spectrum approximately 30 million years ago. This makes our eyes especially sensitive to the effects of periods of light and dark and how our body’s chemistry responds to being stimulated by visible light. When our eyes sense light, it sends signals to the part of the brain that regulates the sleep v. wake cycle. In the past, that light signaling began with the rising sun and ended with the setting sun. Our body used the natural cycle of the day to regulate our states of wakefulness and sleepiness. The proper hormones were released at the proper times to create a restored and alert feeling in the morning, and a sleepy and restful feeling at night. But those days have long since vanished. Artificial light, cell phones, televisions, computer screens, LEDs, and all electronic devices emit an artificial blue light that impacts our body’s natural rhythms, and ultimately our ability to sleep soundly.
Why all the focus on only the blue portion of the visible light spectrum? Research has shown that our exposure to light influences hormone secretion, heart rate, alertness, sleep propensity, body temperature, and gene expression. Moreover, in such studies, blue wavelengths have been found to exert more powerful effects than any other light in the visible spectrum. In other studies, blue light has proven to be responsible for elevating heart rate and body temperature, while reducing sleepiness. In plain terms, blue light keeps the human body in an alert and wakeful state more readily than any other light in the visible spectrum.
Today, blue light exists everywhere. Light from the sun is considered natural blue light, whereas light from electronic devices, fluorescent, and LED lighting are artificial sources. From light coming through the window to our personal device, blue light is everywhere, including our bedrooms. Most of us have the television going in the background while we are scrolling through social media on our cell phone or finishing up that last email before we go to sleep. Some people even sleep with the television on! Any sort of artificial light will trick the sleep regulator part of the brain into thinking it is still daytime. When this happens, the brain suppresses the release of melatonin, the natural sleep hormone, and we will not get sleepy. This throws our sleep/wake cycle off and it can lead to insomnia and chronic sleep deprivation.
To be clear, it’s not simply blue screens and LEDs that cause this issue, any sort of ambient light in a room, such as a very bright lamp, can affect the sleep cycle, throwing off the natural rhythm by two to three hours! When your rhythm is off, sleep quality and quantity is compromised, as is your level of alertness the following day. I often see this with my teenage patients during the regular school year. Many kids have hours of extracurricular activities after school, only to get home around 8 pm, eat late and then have hours of homework on their computers, nonetheless. Couple that with early morning start times and kids that are averaging 5-6 hours of sleep! Our teenagers are painfully sleep deprived. While complaining of headaches and pain and anxiety, our children have become the walking dead in an effort to live up to the expectations schools, and some of us parents, now place on them. Their teenage years are a crucial time of development and the human brain is still growing. This is certainly not a time for your kids to be missing out on sleep. It pains me to see kids on so many meds for anxiety, depression, etc. when the answer is likely right in front of us; our children need more sleep!
It’s really important to shut down devices two to three hours before going to bed. There are many ways to limit blue light exposure and help the body ease into its natural sleep state when you want to go to sleep. First, create a low light atmosphere in the rooms where you spend most of your evening time. Dim lighting and removing blue light-emitting devices two hours prior to sleep are important considerations. Wear yellow-tinted glasses that block the blue light. Or you can install apps on your devices that desaturate the harmful blue light emissions. Lastly, you must keep your room dark while you sleep. Our eyes are so sensitive to light, and we have these extraocular photoreceptors that can sense light as well. Extraocular means that light is sensed by our body, not simply with our open eyes. Our body’s understanding of light and dark exists even when we aren’t conscious. These receptors help maintain our circadian rhythm in response to daylight and night time. They also help control whether our pupils dilate or constrict. Because of this, it is crucial you turn off all ambient light, which includes night lights, outside lighting, the television, and cell phones. Turn on “do not disturb” and airplane mode, stop letting the phone be the first thing you look at in the morning and the last thing before you go to bed.
If you are following all of the proper sleep hygiene tips and still find yourself unable to get a good night’s sleep, set up an appointment or virtual consultation today so that your sleep needs can be addressed. It may be an undiagnosed sleep disorder!