Panther chameleons require two types of lighting: UVB light to compensate for lack of natural sunlight, and a basking light to keep warm. UVB lighting is a necessity for a healthy chameleon. Without UVB and calcium they can develop metabolic bone disease (MBD).
For UVB lights I recommend using the Reptisun or Repti-Glo 5.0 linear bulb, and replace the UVB bulbs every six months. Your chameleon needs to be able to bask no further than 12” from the UVB light in order to benefit from it. Exposure to natural sunlight, when temperatures permit, is better than UVB lights. I recommend you get your chameleon outdoors whenever possible, but keep in mind it needs frequent mistings and a predator-proof cage furnished with plenty of plants to provide shade.
For a basking bulb you can use a standard incandescent 60-75-watt household bulb, or a reptile basking bulb no higher that 100-watts. The bulb you choose depends on ambient temperature and the size of the cage, use which ever bulb gives you your desired temperature.Make sure the lights are on the exterior of the cage, not inside the cage, so your chameleon can’t get too close to the bulb and burn itself.