For the eye to see, light waves reflect off objects, which are received by the eyes. Blue light is one of the several light waves visible to the human eye. It is a part of the natural light from the sun but is also now conducted artificially from electronics. Receptors in the eyes and brain receive these blue light waves.
Blue light directly affects the body’s circadian rhythms. Altering them can negatively impact your health.
At risk is anyone who frequently uses electronic screens, or who spends long periods under fluorescent or LED lighting.
Blue light benefits
Natural blue light is emitted from the sun and is relatively safe. During the day, natural blue light helps increase attention, reactivity, and improves mood. Blue light directly affects the body’s circadian rhythms, which are the body’s biological cycles that run on a 24-hour cycle. These cycles include regulating body temperature, hormones, sleep, and more. The circadian rhythm is associated with certain molecules in the brain which may respond to light exposure, such as melatonin and serotonin, which are important for sleep and mood regulation.
With proper exposure, blue light provides many benefits:
- Potential in improving acne and other skin diseases
- Used as therapy for jaundice in newborns
- Has suggested benefits for Seasonal Affective Disorder
- Is linked to decreased fatigue
- May improve alertness
Blue light also has negative effects when it illuminates from smartphones; tablets; computer screens; flat screen televisions, and other electronics, which are getting more use every day. Note: LED lights and fluorescent lights also emit blue light, which can prove harmful to vision as well.
While blue light can improve how people feel during the day, it also affects how they feel at night - more awake than usual. This is because blue light is known to promote wakefulness around the clock, which means the use of bright LED or fluorescent lights and electronic screens can negatively impact sleep patterns.
It’s important to remember that since blue light stimulates the brain to keep people alert, it also decreases melatonin, which the brain produces during night hours to help promote sleep. Being exposed to blue light through electronic devices during darkness interferes with REM sleep, which is necessary for people to achieve in order to get proper rest.
In other words, blue light exposure in the evening is known to delay melatonin release, which may lead to insomnia and delayed sleep cycles. This is also true for people who sleep with lights, TVs, or other electronics on. Because of these facts, it is recommended that people turn off all electronic devices at least 2 hours before bedtime.
The above facts also hold true for people who sleep with lights, TVs, or other electronics on, so remember to get away from being exposed to blue light at night.
Altering circadian rhythms can negatively impact your health. Not only it may be linked to poor sleep patterns, but it can affect hormones resulting in metabolic problems, and mental health issues like depression and anxiety.
Blue light and eye risks?
Some medical reports state that blue light can damage your eyes; however, recent studies show that there’s little evidence to support this statement. Keep in mind though, that evidence does point out the negative impact blue light can have on circadian rhythms and sleep.
It is a fact that the increased use of screens causes eye discomfort, which results from eye strain, not damage from blue light exposure. Eye strain can develop from the frequent use of digital devices. Symptoms include:
- Dry and watery eyes
- Blurred vision
- Sensitivity to light
- Neck pain
- Burning and red eyes
Who’s at risk?
Anyone who frequently uses electronic screens, or who spends long periods under fluorescent or LED lighting, is exposed to blue light. Exposure to natural blue light from the sun is encouraged with appropriate sun protection.
Blue light avoidance recommendations
- When it comes to screen use, frequent breaks are best. Give your eyes time to rest, and avoid fatigue. The 20-20-20 rule in an option; look at something 20 feet away, every 20 minutes for 20 seconds.
- Avoid symptoms of eye strain by using artificial tear, if needed. Sit at least arm's length from your computer, tablet, or phone screen, and adjust the screen or font size, so you don't need to strain to see fonts and images.
- Blue light glasses are not proven to protect from blue light exposure, and they may or may not help reduce eye strain. There is also no negative effect from using them.
To improve circadian rhythms be aware of what devices emit blue lights, and limit exposure:
- Fluorescent lights
- LED lights
- Computer screens
- Video game consoles
- Handheld devices
Stop use of blue light devices 2 to 3 hours before bedtime. It is also suggested you use dim lights in the evenings and just before bed, or use incandescent lighting rather than LED or fluorescent lights. Use screen dimmers during the day to reduce blue light emissions, and do not use digital electronics after dark.
Use a red or orange lamp at the bedside for reading, since these light waves are likely to be less disruptive to your circadian rhythms.
Blue light caution
Please note that exposure to blue light for skin therapies can cause these side effects:
- Discoloration of skin in infants and adults
- An increase in moles and freckles can develop from exposure
- Headaches may develop
- Use caution in those with photosensitivity
- Harvard Health Publishing. Blue light has a dark side.
- Procedia Manufacturing. Blue Light: A Blessing or a Curse?
- Photodermatology, photoimmunology & photomedicine. Clinical and histological effects of blue light on normal skin.
- Pediatrics. Management of hyperbilirubinemia in the newborn infant 35 or more weeks of gestation.
- PLoS One. A Comparison of Blue Light and Caffeine Effects on Cognitive Function and Alertness in Humans.