Blue Light: What is it and How Does it Affect Us? -- Occupational Health & Safety (2024)

Blue Light: What is it and How Does it Affect Us?

Do you ever think about what staring at screens does to our eyes all day? Harvard Health Publishing investigated blue light and its effects on our sleep and health.

• Jan 10, 2020

Our eyes are continually taking in various forms of light—most of it blue light from screens. We look at our phones before the sun comes up in the darkness of our rooms. We look at computers and tablets at work all day. We come home and watch television. Then we lay in bed looking, again, at our phones long past the sun goes down. What’s in those lumens we take for granted, and how do scientists think it’s affecting our health?

A lot of it has to do with the body’s biological clock, or the circadian rhythm. Our sleep can often get thrown off because of the amount of screen time we have each day. And what’s worse, sleep issues may contribute to the causation of many health concerns like cancer, diabetes, heart disease, and obesity.

Harvard Health Publishing breaks down what blue light is, what kind of exposure is worse than others, the effects it has on sleep, LED light, and how to change your habits for the better.

What is Blue Light?
Have you ever thought of light having a certain colored wavelength? Blue light is exactly that: light with blue wavelengths—which are supposedly beneficial during daylight hours because they boost attention, reaction times, and mood. However, these lights are great for the daytime because they keep us awake, and bad at night because they often impede sleep. The proliferation of electronic screens, as well as energy-efficient lighting, is increasing exposure to blue wavelengths, especially after the sun goes down.

Light and Sleep
No one’s circadian rhythm is the same as someone else’s, but on average, most people’s are about 24 and one-quarter hours. Individuals who stay up late typically have slightly longer ones, while early risers usually fall short of 24 hours. Before the recent influx of electronic screens in 1981, though, a person’s internal clock mostly aligned with the environment, said Dr. Charles Czeisler of Harvard Medical School.

Light Exposure at Night

You might be wondering about how cancer, diabetes, and other concerning health problems tie into the conversation of light. Well, a lot of research is preliminary and needs more information. However, there are some things to be mindful of.

Some studies do suggest a link between exposure to light at night, such as working the night shift, to health problems. However, that is not proof that nighttime light is bad for us or causes these conditions.