Is it okay to have a light over a Chilean Rose Tarantula's tank?

I think is definitely a bad idea to put a light bulb over the tank. I am not aware of any studies that prove me wrong but as they are nocturne animals they rather much prefer to stay in the darkness all their life; having much light can be bad for their tiny little useless eyes. If the place you live is cold, it would be a good idea to place a heating source just below the tank to keep your tarantula warm and safe. It's a bad idea to put some cactus plants or sharp objects, they might look nice but can cause a permanent damage on the fragile body of your lovely pet. My tarantula is now 5 years old, and all her life has been in my dark room. When they change their skin they might look dead so don't worry much about that. You can find many information on the internet (and sorry 4 my awful English)