Research was conducted on 190 people with dementia in 12 care homes over a period of 3.5 years. They were given an activating light quantity of 1,000 lux vertically during the day until dinner time.
I personally find the conclusion, here below on the website of light for later, so fantastic that it was partly the reason for starting this company Sparckel.
I read that substantial prolongation of independence can be achieved in people with dementia by adding daylight indoors. Cognition decreases, depression goes down AND the speed with which you get functional limitations (in dementia) decreased by 53%! The latter impresses me the most.
Enquiries with Eus van Someren himself reveal that 53% is not literally measured in time, but rather that it concerns the ability to dress oneself, for example. One is 53% better able to keep doing that or the reduction of that skill by dementia is slowed down with 53%. How wonderful is that....?! With a powerful bright light during the day, we can extend the independence of people with dementia.
My educated opinion in dementia, depression and sleep problems: strong bright light during the day is an effective medicine, without side effects.
Title: Effect of Bright Light and Melatonin on Cognitive and Noncognitive Function in Elderly Residents of Group Care Facilities: A Randomized Controlled Trial
Source: Article (PDF Available)in JAMA The Journal of the American Medical Association 299(22):2642-55 - July 2008
Riemersma-van der Lek, RixtSwaab, DickTwisk, JosHol, EllyHoogendijk, WitteVan Someren, Eus J W