The Irish Times asks: If you ban your phone before bed, as advised, how can you set your sleep-better app?

“I believe that light is medicine,” says clinical psychologist Dr Michael Breus, a Fellow of The American Academy of Sleep Medicine.

“Light affects our bodies in very unique and interesting ways. There is research to support how light affects disease processes, like Alzheimer’s or Parkinson’s, and mental processes like depression and anxiety, and even sexual processes like libido. You would be shocked at how many different processes light actually affects.”