1. Light, in general, keeps you up at night
Many people, even those without a diagnosed sleep disorder such as circadian rhythm disorder, are sensitive to evening light (learn about different types of sleep disorders here). People diagnosed with this disorder are unable to sleep and wake at the times required for normal work, school and social needs. Shift workers are at high risk for circadian rhythm disruptions, because of their non-traditional schedules. This is called shift-work disorder and can lead to car accidents and other terrible consequences (learn more about shift work disorder here).
All animals and even plants have natural biological circadian rhythms which are controlled by our biological clocks and work on a daily time scale (wake up when the sun rises, sleep when the sun sets). Exposure to artificial light after the sun has set can fool the body into thinking it’s playtime, not sleepy time.
Our blue light blocking glasses block a significant amount of light generally, not just blue light, which can help our bodies ease into sleepy time. This general dimness, which can also be achieved by turning down the lights and brightness on electronics, may reduce the amount of time it takes for you to fall asleep at night.
2. The blue light from TVs & screens suppresses melatonin production, making it harder to sleep at night.
Blue light is particularly harmful to our sleep. This wavelength suppresses melatonin (the hormone that helps to regulate our circadian rhythm) more vigorously than other wavelengths. Many of the new energy-efficient light sources (like those light bulbs you’re supposed to buy) including our favourite electronic devices (smartphones, tablets, TVs), produce high concentrations of this light.
Harvard researchers and their colleagues conducted an experiment comparing the effects of 6.5 hours of exposure to blue light to exposure to green light of comparable brightness. The blue light suppressed melatonin for about twice as long as the green light and shifted circadian rhythms by twice as much (3 hours vs. 1.5 hours).
Scientists at China’s Sichuan University studied the effects of blue-light blocking artificial lenses implanted during cataract surgery. They found improvements in the quality and length of sleep as well as reduced daytime dysfunction due to sleepiness.
Brown or yellow-tinted glasses may reduce light transmittance also, but do not block as much light in the blue wavelength range is orange glasses.
3. You know you should stop using electronic devices before bed, but is that really ever going to happen??
We’ve all heard that you should keep electronic devices, like smartphones, out of the bedroom (read more on why here and tips for making it happen here). I know it’s hard. And when are you going to catch up on Homeland and Game of Thrones if you can’t watch TV before bed? For those of us who can’t give up night-time electronics, our Kensington glasses are essential.
Blue light blocking glasses used in a study of teenaged boys, showed an increase of melatonin levels, even when electronics usage remained the same.