I also have been using bright lights to help stay alert. This has helped a lot getting used to polyphasic sleep. (It also helps to use a sleep mask. Bright light while awake, no light while sleeping.) Since I started, I have noticed that I have less need for this effect, but it is still nice.

I had looked into the light therapy bulbs, but the price made me think I should at least try the brighter conventional bulbs first, and this turned out to work fine.