It’s well established now that blue light has a disruptive effect on sleep as it affects the production of melatonin more than any other wavelength of light but it’s not only effect of light in the hour before bedtime that’s important. Much of our day is spent indoors in often poor quality light conditions. But how bad is it? The Lys light tracker can help with that, and I find out more from Christina, CEO and Founder, at the Wearable Technology Show. UK firm Lys Technologies have developed Lys as a light tracker for the indoor generation and physically it’s a small round device that clips onto clothing. The intention is that you get Lys as close as possible to your eyes so that the tracker receives a similar amount of light radiation. Lys not only measures the intensity of light falling on it, but also the quality, which for light is represented by its wavelength. Most of us are familiar with the light spectrum which runs from infrared through the ultraviolet but white light is not a single colour: it’s made up of many colours (remember the experiment with the prism in school?). By slightly adjusting the composition of the light, you can end up with bluish whites and warm (reddish) whites – you might have seen these descriptions on LED lighting. The other side of the coin is that humans have a circadian rhythm that’s aligned to the 24 hours of the day (give or take). This rhythm is reinforced by daylight received in the eyes but as we now spend so much of our time indoors, sometimes the rhythm becomes disrupted and we have difficulty sleeping. One of the key differences between natural and artificial light is that daylight is “full spectrum” with a broad range of wavelengths, whereas most bulbs only approximate daylight with a smaller number of wavelengths. Anyway, that’s all by-the-bye. The important thing is that the Lys tracker can measure the light falling on it during the day, and provide this information to you via an app, showing you the quality, intensity and duration of the light. This guides you to help get the “right light” to reinforce the circadian rhythms and get a good night’s sleep. Just in case you are wondering, Lys means light in Danish, and is a nod to Christina’s Danish roots. The Lys tracker is available to purchase now for GB£89 but what I’m most interested in are some of the possible future developments where information from Lys is fed into smart lighting systems like Philips Hue or LIFX which can adjust their colours to prepare you for bed. That’s really where the smart home becomes smart.