I usually race in some light, but not too much. If it's completly dark I get distracted by how much the screen is lighting up the room. Makes my eyes hurt after a while
I need some light in order to race properly...unless it's a rainy race because then the screen won't show so many bright colors, so then it won't feel like I'm trying to race while staring right into a light bulb
But I do like to race in the dark. Feels nice. Especially in the cockpit view in night or rain races. Cosy
I race in dark, because then I can be 1 with the pc and the sim lol.. if I race in the light I race with some speakers besides my screen. and I dont want to look in a cockpit when racing while Im watching my speakers O_o
If during the day I normally drive with the curtains closed so I don't have the sunlight glaring off the screen as the windows are south-facing.
If driving at night I normally drive with the spot light at the opposite end of the room turned on, or the tv also at the opposite end of the room turned on so that I have a bit of background light in the room as otherwise I get tired quickly and lose concentration.
Watching the screen in total darkness is not really pleasant. All the light is annoying to the eyes, well mine anyway. But too much bright light just around the screen is also not good. I prefer to have a lamp lit in the background so that the whole room is properly lit.