The Blue Light Effect, Is It Good or Bad?
Thu, September 29, 2022

The Blue Light Effect, Is It Good or Bad?

A blue light is a color in the visible light spectrum seen by human eyes / Photo Credit: Pexels


Blue light is considered environmentally friendly as it helps to regulate sleep and wake cycles, also known as the circadian rhythm. It also helps boost alertness, elevate moods, heighten reaction times, and increase one's overall feeling of wellbeing. However, blue light is dangerous after sundown as research shows that one's circadian rhythm can go awry. Blue light can disrupt sleep and this could potentially result in cancer, heart disease, obesity, and diabetes.

What is Blue Light?

Blue light is a color in the visible light spectrum seen by human eyes. It has the shortest wavelength and the highest amounts of energy. Approximately one-third of all visible light is high energy blue light. Sunlight is the most significant blue light while artificial sources of blue light can be found on digital screens of televisions, smartphones, computers, laptops, tablets and gaming systems, as well as other electronic devices, and LED and fluorescent lighting.

How Blue Light Affects Health, the Good & Bad

Blue light has both short and long term effects on health. The long term effects may be discernible much later in life but the damage it may cause can be dreadfully damaging. The short term effects are dry, red, watery and itchy eyes, and headaches and trouble falling asleep technically termed as Digital Eye Strain (DES). DES is the consequence of extensive computer use, exposure to blue light, and prolonged focus on an object.

It is, however, not advisable to completely obstruct blue light as it has significant health benefits as well. It sparks off essential physiological responses like pupil constriction and circadian rhythm synchronization. Inadequate exposure to blue light can cause myopia or nearsightedness.


Inadequate exposure to blue light can cause nearsightedness (myopia) / Photo Credit: Good Free Photos


The long term effect of overexposure to blue light brought about by late-night Netflix binging, Instagramming, online gaming, and increased use of LED screens can lead to permanent cellular damage and loss of vision called Age-Related Macular Disease (AMD), permanent cellular damage and loss of vision. AMD has no cure once diagnosed.

A recent study at Oregon State University reports that blue wavelengths coming from light-producing diodes damage cells in the brain as well as retinas. The study was conducted on the common fruit fly, an organism that shares cellular and developmental mechanisms to humans. Over daily 12-hour exposure to led blue light, results showed accelerated aging, damage to retinal cells and brain neurons, and impaired locomotion. Even mutant flies that do not develop eyes and eyeless flies exhibited brain damage and locomotion impairments. Their lifespan was shortened dramatically. Eileen Chow, a research assistant and co-author of the study, however, cautioned that further studies on the damaging effects of the blue light need to be done to confirm applicability to humans.


Studies revealed that higher exposure to blue lights may lead to higher risk of developing breast and prostate cancer / Photo Credit: Peakpx


In another study conducted by the Barcelona Institute for Global Health (ISGlobal), results showed that study participants exposed to higher levels of blue light had a 1.5 and 2-fold higher risk of developing breast and prostate cancer respectively, compared to the less-exposed population. The study also showed that blue light wavelength signals the brain to suppress melatonin, a hormone that helps regulate the sleep-wake cycle. When melatonin is suppressed at night, the capacity to fall asleep is altered by as much as three hours. Martin Aubé, a physics professor at CÉGEP in Sherbrooke, Canada, attests that melatonin production and secretion are decreased depending on the intensity and wavelength of artificial light, particularly in the blue light spectrum.

Dr. Amy Shriver, UnityPoint Health Pediatrician, says over-exposure to blue light causes trouble with sleeping, increases the risk of depression, diabetes, and cardiovascular problems. 

Similar results were also observed in the study by the World Health Organization's International Agency for Research on Cancer (IARC). The study results indicated an association between exposure to artificial light at night and disruption of the circadian rhythm, and breast and prostate cancers.



Minimizing Blue Light Exposure

There are several ways to protect oneself from the negative effects of blue light. These include the following:

Power down. Since digital devices emit blue light that affects sleep, cut out screens two to three hours before bedtime. 

Look at the settings of your digital device, and adjust screen brightness and turn on night light filters. Lessening screen brightness can play a vital role in reducing blue light exposure. 

Use devices with smaller screens. The exposure to blue light is proportional to the screen of the digital device as well as the distance between the screen and the eyes. View the screen from a distance.

Change home lights to warm lights or “smart” lights to make them sleep-friendly. Warm lights do not have an effect on melatonin levels compared to bright lights. 

Get protective eyewear like a pair of blue-light blocking glasses or lenses with anti-reflective coatings that can block blue light exposure.

Reset your circadian rhythm by getting most of the blue light exposure during the day through more sunlight or a lightbox.

The world today is glued to electronic devices. Being exposed to blue light is now a natural phenomenon. However, blue light exposure can be reduced, as long as you work to avoid it.