Snakes do not require any type of lighting. They are carnivorous and get all their nutrition directly from their prey...not requiring UVA or UVB to sythesize certain vitamins and minerals like the omnivores and herbivores.
I personally provide fluorescent lighting on a timer for a number of my snakes...they live in the basement and this provides an artificial photoperiod, a fake "daytime". Cornsnakes are crepuscular, which means active at dawn and at dusk...so artificial photoperiod can be important in a completely dark basement. Otherwise I heat any tanks with a UTH (Under Tank Heater). This provides belly heat...which is good, but not absolutely necessary. The UTH also does not lower the humidity as much as lights or emitters...
Lights and emitters lower the humidity substantially IMO, and may cause need of artificially supplementing (misting, etc.) the humidity in your enclosure.