LG Study Says OLED TV Leads To Better Sleep

We’ve all heard that screen-time before bed is bad for sleep. If you struggle to fall asleep at night, as I almost always do, you’ve probably been told to turn off your phone and avoid watching TV for at least an hour or two before going to bed. There are two main reasons why we’ve been hearing this more for the last 20 years or so than we did before. The most obvious is the advent of smartphones, which blast our eyes with light from just a few inches away, and which follow many of us to bed. Previous generations of technology simply weren’t in our faces with the same frequency from morning to night. But the focus on blue light in particular also began around 20 years ago when scientists discovered that there is a type of photoreceptor in the eye that detects light specifically “for circadian responses, rather than visual responses,” according to Stuart Peirson of Oxford University’s Sleep and Circadian Neuroscience institution (SCNi). In a 2018 interview with The Guardian, he explained that these light-sensitive responses include “setting the circadian clock, regulating sleep and alertness, and also things like hormone responses, such as melatonin.” Blue light, it seems, affects these rhythms more than other parts of the light spectrum. Unfortunately for us, LED-based devices such as phones and tablets, laptops, and even regular LED light bulbs, emit more blue light than the incandescent bulbs of the 20th century, and that may be one reason why more people appear to be suffering from poor sleep hygiene and related health issues. A major study published in The Lancet Psychiatry examined data from over 90,000 middle-aged adults and found that those with disrupted sleep were more likely to suffer from mental illness, including depression and bipolar disorder.

Blue light is not sinister. You get changes particularly in the blue part of the spectrum around dawn and dusk and so our bodies have evolved to be able to detect these changes, because they are what’s important for setting our clocks. It’s just that we’ve subsequently invented devices that emit light and we’ve filled our environment with them and made them addictive. If you go to bed at night and stare at your bedside lamp for 10 minutes, that will (also) shift your clock, it’s just that nobody does that.

— Stuart Peirson of Oxford University’s Sleep and Circadian Neuroscience institution (SCNi)

OLED TV for Better Sleep?

But there may be good news for those of us who like to watch TV before bed. A new study published by OLED panel manufacturer LG Display suggests that OLED screens are less harmful than their liquid crystal counterparts. Unlike LED-backlit LCD screens, OLED devices are self-emissive, meaning that each pixel creates its own light. And the quality of that light seems to be better for sleep. The study found that LG Display’s OLED TV panels actually help viewers maintain healthy sleep patterns, and the company is now boasting that its TVs are proven to be “Sleep Friendly,” supporting eye health and overall wellness. The clinical study examined the impact of TV panels on sleep in conjunction with researchers from Kookmin University in Seoul, South Korea. It’s worth pointing out that this was a fairly small-scale study, following 40 adults over a two-week period. During the study, the test subjects were divided into groups watching the same content on either LCD or OLED TVs. Researchers measured levels of the sleep-inducing hormone melatonin in both men and women throughout the test period.

According to the resulting report, melatonin secretion in the LCD TV group dropped by an average of  2.7% after two hours of viewing. This appears to confirm what scientists have warned about with respect to blue light exposure and its potential effects on circadian rhythms. But surprisingly, melatonin secretion in the OLED TV group actually increased by an average of 8.1% after test subjects watched identical content for the same period of time. The report explains that the human body needs melatonin to rise in the evening to prepare for sleep, and that when melatonin secretion is disturbed, sleep disorders can follow. According to LG Display, modern LCD panels emit 70-80% blue light, owing to their continuous reliance on strong backlighting, provided by LEDs. LG Display's self-emissive OLED TV panels emit just 36% blue light, according to the report.

In addition to minimizing the negative impact on melatonin secretion during viewing time, OLED TVs have been shown to be effective in maintaining viewers’ healthy sleep patterns through greater activation of their parasympathetic nerves, which are responsible for feelings of comfort.

— Professor Kim Chang-wook, Research Team Leader from Kookmin University

Eyesafe Certification for TVs?

While I don’t question the results of this study, I do tend to take studies sponsored by interested corporate parties with a grain of salt. But these results do confirm previous findings that LG Display’s OLED panels are supportive of eye and body health in ways that LCD screens can’t match. In 2023, LG Display’s OLED TV and monitor panels were the first in the industry to be certified as “Circadian Friendly” by TÜV Rheinland, a Germany-based testing, inspection, and certification organization that tests technical systems and products around the world. LG Display’s OLED TV panels are used not only in LG-branded TVs, but also in some TVs made by Sony and Samsung (sold in the USA) and by Panasonic and Philips (sold in Europe). These panels reportedly have the lowest level of blue light emissions among all existing TV panels, and they lack the screen flicker found in some competing technologies — a phenomenon that can potentially lead to vision loss, according to LG Display. Because of these qualities, LG Display’s OLED panels have earned the “Eyesafe” certification created by the U.S.-based Eyesafe company, in association with TÜV Rheinland. Eyesafe is a supplier of advanced blue light mitigating technology, solutions, and standards. In order to satisfy the requirements for Eyesafe certification, a product must be shown to have blue light emissions and color performance that align with international standards and guidelines developed by the American National Standards Institute (ANSI) and the International Commission on Non-Ionizing Radiation Protection (ICNIRP). In addition to receiving Eyesafe certification, LG Display’s OLED panels have been verified to be “Flicker Free” and “Discomfort Glare Free” by the global independent safety science company UL (Underwriters Laboratories). Anecdotally, one of the reasons why I bought the Sony OLED TV that I currently use was that I found it more comfortable to watch than LCD TVs. Sure, I appreciate the deep blacks and lack of blooming, but I also find OLED TVs to have an easy watchability that reminds me of the best plasma and CRT TVs of yesteryear.

We will introduce products and technologies that can provide differentiated customer value based on OLED panels that are safe for the human body while offering the best image quality.

— Soo-young Yoon, CTO and Executive Vice President at LG Display

As much as I would like to be able to tell you that switching to an OLED TV will cure your insomnia, that’s probably not the case. (It certainly hasn’t done the trick for me.) And the results of LG’s study must be taken within the context of big-picture factors that affect sleep, including things like exercise, stress, your sleep environment, and the times at which you go to bed at night and wake up every day. I’ve seen research suggesting that going outside for just 20 minutes at lunchtime every day can improve your sleep more than limiting screen-time at night. The same goes for maintaining a dark, cool, and quiet sleep environment, getting regular exercise, and keeping to a regular sleep schedule, even on weekends. It’s likely that multiple factors contribute to a person’s overall sleep quality, and that can have significant implications for overall health. If OLED panels actually promote better sleep health, perhaps I finally have an excuse to replace my ancient iPhone and upgrade to a newer model, most of which use OLED displays nowadays. Will sleep quality factor into your next TV or gadget purchase? Share your thoughts in the related forum thread below.