According to a 2013 patent application, Valkee’s earlight shall work against

• “anxiety, depression, delirium, Alzheimer’s disease, ADHD, infertility, migraine, seasonal affective disorder (SAD), cancer, obesity, circadian rhythm sleep disorders, jet lag, shift work disorder, Parkinson’s disease, burning mouth syndrome, fibromyalgia, restless legs syndrome, social anxiety, hypertension (HTN), cognitive impairment, migraine, headache, social phobia, Generalized anxiety disorder (GAD), chronic pain, and decreased cognitive performance.”
  (emphasis added, thanks to roskatiede.wordpress.com)

Valkee’s Timo Ahopelto has, via his Lifeline Ventures fund, also a major stake in Oncos Therapeutics. There he is also on the board. That’s a pharmaceutical company, which – as the name tells – develops cancer treatments. Hope they know what they are doing.