More light (excuse the pun) shed on the sleep / blue light issue

In the same way that excessive blue light hitting the brain during the darker hours before night can inhibit the release of the sleep regulating hormone melatonin (and thus cause sleep problems), so can - during the daylight hours - not getting enough blue light cause a disruption of the night-time sleep cycle.

And a surprising way this can happen, for elderly people, is through the development of cataracts. Cataracts increase the opacity of the lens, and thus - during daylight hours - reduce the amount of blue light reaching the brain.

Solution? Have your cataracts done! Fascinating...