Apple's addition of a blue-light reduction feature into an update to its operating system is the first acknowledgement by a major manufacturer that blue light can be a health hazard.
The latest update of its operating system, iOS9.3, includes a night-time screen mode with reduced intensity in the blue part of the visible spectrum. The move will be seen as an endorsement of those who have been arguing that the health issues of blue light need to be addressed by industry.
It’s long been known that blue light or, to be more accurate, the quantity of blue within the white light spectrum, helps to suppress the production of the sleep hormone melatonin. Exposure to light at night has been linked to conditions like cancers, diabetes, heart disease and obesity – and while the jury is still out on how blue light can trigger these disorders, its deleterious effect on health is well established.
A recent Harvard Medical School Health Letter claimed: ‘light at night is bad for your health, and exposure to blue light emitted by electronics and energy-efficient lightbulbs may be especially so’.
LED lighting has a pronounced spike in the blue part of the spectrum, as the vast majority of white LED lighting is the result of a conversion of pure blue light using phosphors.
The European Commission-funded Lighting for People, a web-based platform of research on solid-state lighting in Europe, has published recommendations for lighting at home, which include:
Provide lighting that is cool in appearance and at higher levels during the daytime, but shift to warmer light at a lower illumination level in the evening.
Applying the positive nature of blue-enriched light, provide higher lighting levels in workplaces to improve alertness.
Excessive use of tablets and computer screens in the evening will delay sleepiness.
Have warm, low level illumination at home in the evening and refrain from using blue-enriched screens during that time.
There are already examples of installations featuring so-called circadian lighting, where the colour and intensity of light varies thoughout the day to match our natural rhythms. At the professional end, lighting companies are investigating wireless lighting solutions, based on LEDs capable of shifting their white light from cool to warm depending on the time of day. And at the consumer end of things there are a number of lamps coming on stream that claim to support the circadian rhythm, either by shifting their colour temperature, or because they are aimed directly at the late-night lighting market.
A recent installation at Kongsgardmoen School at Kongberg, in Norway, is designed to assist teachers in their interaction with students by giving them the ability to change the tone of the lighting depending on the class activity. Early reports suggest that students are reacting positively to the new lighting, with improved concentration and behavior throughout the day.
But established metrics remain elusive. Practitioners say hard data is needed to create a standard for what circadian lighting should look like from a technical standpoint. Typically, the lighting industry delivers product within the capability of current technology and the developments around the LED revolution has brought this topic into a sharper focus.
Internet of Things-based lighting control, data capture and security will be a key theme of LuxLive 2017, which takes place on Wednesday 15 November and Thursday 16 November at ExCeL London. For more information, and to register for free, click here.
Photograph by japanexperterna.se