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UnityPoint Clinic Urgent Care - Sunnybrook

5885 Sunnybrook Drive
Sioux City, IA 51106

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Is Blue Light Actually Harmful?

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Man sitting in front of a computer
The average American adult spends as much as 12 hours a day in front of a screen. Teenagers aren’t far behind with an average of 8 hours a day. The light given off by digital screens, as well as what’s emitted by natural sunlight, is called blue light. Man-made blue light, the stuff we absorb while sitting at a computer or looking at our devices, can be disruptive to the body, explains UnityPoint Health Pediatrician, Dr. Amy Shriver

What is Blue Light?

Blue light is a color that’s visible on the light spectrum, meaning, we can see it with our eyes.  

“Daylight contains a lot of blue light. This helps our internal clock stay aligned with the natural environment. Blue light, such as that from LED bulbs, fluorescent lights, tablets and smartphones has the most effect on our circadian rhythms,” Dr. Shriver says. 

A circadian rhythm is like an internal clock for your body. It helps regulate your awake and sleep time.

What are the Effects of Blue Light?

Dr. Shriver says over-exposure to blue light can have a major effect on our ability to fall asleep and can also reduce our REM sleep which is important for restfulness. It’s a common problem for adults, for example, who work late into the night on computers. 

“Sleep disruptions would happen if you were seeing blue light beyond daylight hours, and even one day of extended blue light exposure can affect how you sleep. This can be significant if you are a teenager, who around puberty, goes through a natural shift in their sleep cycle that keeps them up later at night” Dr. Shriver says.

The pineal gland in our brain secretes melatonin, a hormone that helps regulate your sleep-wake cycle and increases about two-to-three hours before bedtime to help you sleep. Blue light can delay the release of melatonin, which can shift our ability to fall asleep (some studies show up to three hours!)

Dr. Shriver says this over-exposure to blue light, which can cause trouble with sleeping, has also been shown to increase depression, diabetes and cardiovascular problems as well. The American Optometric Association say spending a prolonged period in front of a screen can also lead to eyestrain, headaches, dry eyes and neck and shoulder pain.

Do Blue Light Blocking Glasses Work?

One possible solution that may help reduce the amount of blue light we absorb from digital screens are blue light filter glasses, also known as blue blockers. 

According to, blue light filtering glasses originated from the NASA space program back in 1986. Astronauts used them to protect their eyes from strong UV rays. A sunglasses manufacturer in California took note and designed a pair that blocked not only UV rays but blue rays, too. 

Today, they’re being marketed by companies all over the world and cost anywhere from 15 dollars to 95 dollars a pair, depending on the brand. For those who want to spend the money, Dr. Shriver would recommend blue light glasses to people who work on computers or screens into the evening hours — usually after 6 p.m.

What are Other Ways to Protect Yourself Against Blue Light?

Dr. Shriver says there are several things you can do, outside of buying blue blocking glasses, that are totally free and can help reduce the negative effects of blue light before bed, such as: 

Power down. Cut out screens two to three hours before bedtime.
Look at settings. Look into apps/settings to reduce the amount of blue light emitted.
Use red light. Swap out fluorescent/LED night lights in bedrooms and bathrooms for dim red lights, which have the least effect on melatonin and circadian rhythms.
Get some sunshine. Expose yourself to plenty of daylight (and good nutrition and exercise) during the day for improved night sleep and a boost in mood and attention.