Lockley is concerned about young people being exposed to blue-enriched electronic devices in the evening
Professor Steven Lockley presented on ‘The right light at the right time; redesigning light for alertness, sleep and health’, at a Daylight Group meeting in May.
Light is the primary stimulus for circadian entrainment and, where circadian rhythms used to be considered important only for sleep, it has become apparent that they drive biological processes in the body by turning genes on and off at the ‘correct’ time. Exposure to light that has a higher colour temperature (generally, higher blue content) in the hours before bed will reduce the quality of slowwave sleep – the restorative stuff.
Professor Lockley is particularly concerned about young people being exposed to blue-enriched electronic devices in the evening, because growth hormone is only produced during deep sleep. He outlines two general principles:
- In an environment where people don’t sleep, you should try to make them alert. Spectral adjustment is not required unless for specialised use – for example, in dermatology.
- In environments where people sleep, there are advantages in being able to reduce the blue content and lower the intensity in the evening.
Dr Richard Hobday delivered a second presentation on ‘Myopia and daylight in schools: a neglected aspect of public health?’ Videos of the presentations, and others, are available here.