Q: what do you do if camera light doesn't come on when you open facetime or skype?

Hope info from this article is helpful.

http://support.apple.com/kb/HT2090

Reset SMC.     http://support.apple.com/kb/HT3964

Choose the method for:

"Resetting SMC on portables with a battery you should not remove on your own".

If you have iStat installed, update it.

Best.

Dominic23, I think you are also forgetting that it is no longer called the iSight camera, it is called the FaceTime camera, so that article might be out of date. Also, I think that is for the external iSight webcam that Apple sold.