Yes, it depends on the person...the timing of the lights.

The light wavelength is a blue green...and very effective at resetting you. I am taking less naps this week. Hubby got fed up with me sleeping so much! LOL

I have a old post on Depression here when I first bought the visor:
http://neurotalk.psychcentral.com/sh...ighlight=visor
This link gives another link for further comments.

I didn't seem to need it last year. I originally was still working when I first purchased the visor. (my neck and shoulders were giving me much trouble then).

You can walk around with this visor, but you have to be careful as it changes what you can see, esp. the feet. So I only use it when sitting down, and mostly on computer.

The price has come down quite a bit since I bought mine, and also one for my son who was interested also.

It is easy, and after the first day---shock at the color/brightness-- there is nothing to it. I leave mine plugged into the charger all the time, so I am pleased that the battery is still good. It has an auto shut off feature and two intensities of light. I only use it on the less intense one. Most of the time for 1/2 hr. But sometimes I increase to 45 minutes.