Screen time is something we’re hearing a lot about at the moment. In the UK alone, people check their smartphone on average every 12 minutes of the waking day, according to a report from Ofcom.
This increased dependency means that display technology is having to become more visually pleasing (whiter, brighter and thinner) and has also resulted in a number of interesting developments, such as flexible electronics.
For this to be made possible, engineers have had to start using different materials such as organic LEDs (OLED) and liquid crystal displays (LCD).
These materials must emit light at very short wavelengths to deliver demands such as brighter screens. The issue is that they’re emitting higher levels of high-energy visible (HEV) blue light – an intense band in the light spectrum that reaches to the back of the retina.
“Devices are becoming more appealing to the eye, but with people on devices more than they’re sleeping, this exposure to displays is also opening up health concerns,” explains Justin Barrett, CEO at Healthe, the global supplier of Eyesafe – a health protection driven technology company.
“I see many patients everyday commenting that they have tired, dry and sore eyes. It turns out that device use is impacting how my patients are functioning and we call these set of symptoms Computer Vision Syndrome (CVS). It is important that we pay attention to the impact of HEV blue light and how it impacts people,” notes Dr. Bill Trattler, a refractive, corneal and cataract eye surgeon.
Barrett identifies the trend of devices getting ‘closer to the eye’, suggesting that as we see technologies such as virtual reality (VR) become more mainstream, the impact on eye health could potential worsen. “There are so many unknowns about what kinds of long-term affects this could have – and with VR and augmented reality (AR) it may be that we won’t know until decades in the future what prolonged, ‘up-close’ screen time will do to our health.”
Children (who are using devices from a much younger age) in particular are at risk when it comes to HEV blue light, as Barrett explains, “It’s not until minors become teens that their eye develops a natural filter to take out the 400-360 band of the light spectrum (HEV blue light). For adults, around 25% of this is reaching the retina, for children it’s 60%.”
In partnership with Zagg, Healthe and Eyesafe, Barrett explains that the threesome has developed a new type of a blue light filtering technology which uses a surgical-esque technique to ‘cut out’ the HEV blue light.
Filtering light from screens is not a newly found tech, in fact there are apps available to do this. However, according to Barrett these solutions are “taking a sledgehammer to the colour spectrum”, filtering not just the HEV blue light, but all of the spectrum. This makes screens appear discoloured, a quality that is less than desirable to the consumer.
“Blue light occurs naturally from the sun and in small doses is good for your health,” explains Barrett. “It’s regulating your body sleep/wake cycle – which is why staring at a screen at night-time can have a negative effect on your sleep.” Noting the importance of a small dosage of HEV blue light, Barrett says the technology only removes “the harmful part of the HEV blue light spectrum”.
He adds, “By doing this we keep colour integrity and a small part of the blue light that is good for you.”
To accomplish this feat, the filter known as ‘Vision Guard’ uses a dye technology that focuses on very narrow bands of the spectrum. This is either integrated into the display itself or directly into a screen filter, says Barrett.
“Our view is, we may not know the full extend to how this will affect health, but if you can take preventative measures, then why not? Especially if you’re doing it without sacrificing the display.”
It seems that TUV Rheinland has noted the harmful effects of HEV blue light too, with the release of its RPF standard, and Barrett thinks this is only the beginning. “We foresee legislation emerging that will require standards to remove blue light from future displays."
Balancing display capabilities and appearance with human health seems like it will be the next important design consideration, and thanks to Eyesafe it may be easier to incorporate such a solution into devices.
However, with tech developing rapidly, who knows what new display challenges lie on the horizon. At least for now, the problem can be satisfied without scarficing screen quality.