For many of us, screens are an inevitable part of our day. Whether it’s working on a computer in the office, watching a movie on the TV at night, or checking social media on a smartphone, we’re constantly exposed to screens. Many of these screens and other light sources use light-emitting diodes, or LEDs, which produce significant amounts of blue light.
The negative effects of blue light
Studies have shown that exposure to light with a short wavelength, especially blue light, can disrupt your circadian rhythm, the human body’s internal clock that takes the form of a 24-hour cycle and governs certain physiological processes such as sleep and eating. This particular type of light can prevent the release of melatonin, making it more difficult to fall asleep or reach the deep sleep stage of sleep.
Researchers also believe there may be a link between exposure to bright artificial light and weight gain, insulin resistance, obesity and other metabolic disorders. However, organic light-emitting diodes, or OLEDs, produce less blue light than LEDs. Is it possible that the negative effects of screen exposure are reduced with this display technology?
What the studies reveal
In a study published in the journal Scientific Reports in June 2021, researchers from the University of Tsukuba in Japan compared the effects of LEDs, commonly used for their energy-saving properties, and OLEDs on the physical processes that occur during sleep.
Polychromatic white LEDs emit a large amount of blue light, which has been linked with many negative health effects, including metabolic health. In contrast, the polychromatic white light emitted by OLEDs contains much less blue light. “Energy metabolism is an important physiological process that is altered by light exposure,” explained senior author of the study Professor Kumpei Tokuyama. “We hypothesized that compared with LEDs, OLED exposure would have a reduced effect on sleep architecture and energy metabolism, similar to that of dim light.”
To test this hypothesis, the Japanese researchers exposed ten participants to LED, OLED, or dim light for four hours before they slept in a metabolic chamber. The researchers then measured energy expenditure, body temperature, fat oxidation, and melatonin levels during their sleep.
“The results confirmed part of our hypothesis,” explained Professor Tokuyama. “Although no effect on sleep architecture was observed, energy expenditure and core body temperature during sleep were significantly decreased after OLED exposure. Furthermore, fat oxidation during sleep was significantly lower after exposure to LED compared with OLED.”
“Thus, light exposure at night is related to fat oxidation and body temperature during sleep. Our findings suggest that specific types of light exposure may influence weight gain, along with other physiological changes,” says Professor Tokuyama. We can therefore assume that OLED displays, and therefore OLED TVs, have less disruptive effects on sleep quality.
Should you choose OLED technology for better sleep?
In more concrete terms, this study shows that having screens in your home that emit less blue light can improve your well-being and that, as a result, OLED TVs can help reduce the negative effects on your sleep quality and metabolism if you enjoy late-night home theater sessions or can’t stop binge watching episodes of your favorite Netflix series until late at night.
In addition to the potential health benefits of OLED displays, blue light emission as well as the impact on sleep and eye health are features that companies now take into consideration. In 2020, Underwriters Laboratories classified Samsung 4K and 8K TVs as being “no photobiological LED hazard”, while Verband Deutscher Elektrotechniker granted them an eye safety certification. The Chinese brand TCL has also met the requirements of the EyeSafe Display standard, which seeks to reduce the negative impacts of blue light on vision.
If you’re planning to change your TV, a screen with lower blue light emission is recommended. To learn more about OLED and QLED technologies, read our article OLED TVs and QLED TVs: which should you choose?