I’ve been trying out using LED light to stimulate my brain with positive results; for details, see my writeup with graph/data/code at http://www.longecity.org/forum/topic/72558-lllt-usage-correlates-with-productivity/
As far as I know, LLLT works on different principles than light therapy. Valkee is just about affecting circadian rhythms, much like lightbox therapy or melatonin supplementation, and broad-spectrum natural light (maybe bluish) is all you need. LLLT’s postulated mechanism is through specific near-infrared wavelengths hitting a particular protein in cell’s mitochondria and supercharging cellular metabolism. See http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3288797/ , http://www.gwern.net/docs/nootropics/2013-rojas.pdf , & http://journal.frontiersin.org/Journal/10.3389/fnsys.2014.00036/full So unless Valkees were targeting roughly the same wavelengths, they should be doing different things.
Interesting… I also wonder how the amount of irradiance at the devices wavelength (?) compares to what you get from being outdoors in the sun?
I think I saw a calculation of that somewhere on Longecity, but it’s impossible to find anything in it. IIRC, the conclusion was you got much more of the relevant wavelengths than sitting in the sun because sunlight spreads the energy over such a wide spectrum and a lot of it in the visible.