Sleep is essential to our lives. It doesn’t just determine how productive we will be; it also affects our mental and physical well-being.
The ideal amount of sleep that an adult requires to function at optimal levels is 7 hours and above. For teenagers, it's 8 hours and for children, 12. Unfortunately, however, most people tend not to get enough sleep in quality or quantity, and the reason for this is excessive exposure to blue light!
What Is Blue Light?
Blue Light is a part of the white light that is visible to human eyes. And white light is made up of red, indigo, blue, green, yellow, violet, and orange colors. Each of these colors represents light as well and has different wavelengths. For example, red light has the longest wavelength.
Blue light’s high-energy waves are similar to UV rays but visible to the human eye. It has a short wavelength and high energy, making up more than half of all bright light.
With a short wavelength of 380 to 500 nm nanometers, blue light can directly penetrate the cornea and hit the retina, causing retinal damage. Approximately one-third of all visible light is considered high-energy visible (HEV) or “blue” light.
But blue light isn't all bad! In fact, it's naturally found in sunlight. The right amount of blue light actually lifts our mood and supports a healthy circadian rhythm. So, the trick isn't to eliminate blue light entirely; it's to find light sources that contain healthy amounts of blue light!
The artificial sources of harmful blue light include:
- Smartphone screens
- Smart Tablet screens
- Television screens
- Computer monitors
- Fluorescent & LED lighting
How Does Blue Light Affect Sleep?
Too much exposure to harmful blue light inhibits the production of melatonin, a hormone that controls the circadian rhythm. If you’ve ever wondered how your body shuts down when it is nighttime, it is because of melatonin!
When it starts to get dark, the pineal gland releases the hormone melatonin, making you sleepy. During the day, sunlight, precisely blue light in sunlight, serves as an inhibitor to melatonin production. However, as the day comes to an end and we get exposed to lesser intensity of blue light from the sun, more melatonin is produced to initiate the sleep cycle of the circadian rhythm.
This seamless process has been disrupted by the presence of many artificial sources of blue light. When it starts to get dark outside, we introduce fluorescent lamps for reading or stare at a screen while we wind down from the day with Netflix or a book. Instead of the pineal gland producing melatonin when it should, it doesn’t. Lower than optimal levels of melatonin at night result in poor sleep quality and quantity!
Harvard University researchers studied the effects of 6.5 hours of exposure to blue light vs. green light. They found blue light suppressed melatonin and shifted circadian rhythms by twice as much as the green light.
How to Protect Your Eyes from Blue Light
Smartphones, tablets, and almost all artificial sources of blue light are here to stay. But how do you protect your eyes and maintain a healthy sleep schedule?
Here are some steps you can take:
- Stay away from blue light technology at least 2 hours before going to bed
- Make sure both your day and evening task lighting blocks out as much blue light as possible
- Read a book instead of looking at an electronic device and get a suitable reading lamp
In addition to blue light exposure suppressing melatonin production, reading in the dark or dim light causes eye strain. Eye strain not only makes us more vulnerable to short and long-term vision problems, but it further aids in a poor night's sleep. Protect your eyes, your mind, and your productivity by reducing your exposure to harmful blue light while investing in light that is bright and safe for reading.