I have chameleon(s) in my office room. At night, when I'm at the computer, my monitors shine directly at this particular one and keep her awake. To prevent that, I place a dark, soft, lightweight blanket on the spot she sleeps to prevent light hitting her eyes.
Note: From my observations; panther chameleons are very susceptible to light shining in their eyes at night where as veileds don't seem to wake up with dim room lighting.