How to Turn off the Webcam Light on a MacBook
MacBook and iMac computers come with a built-in iSight camera that allows you to take pictures and video using a variety of applications. Whenever an application that utilizes the iSight camera is running, a green light appears near the camera to indicate that the camera is on. You cannot disable the light from coming on through the iSight's settings. If you want to turn off the iSight's light, you must shut down the application that is using the webcam.
Press and hold the Command key, then press the Tab key. A list of running applications opens.
Press the Tab key while holding the Command key to scroll through the list.
Highlight the application that is using the iSight camera. Default applications that utilize the webcam include iMovie, Photo Booth, iChat and FaceTime. The camera also works with most third-party messenger applications, such as Skype and Yahoo! Messenger. The webcam also works with several security applications, including RemoteSight and EvoCam.
Press the Command and Q keys simultaneously to close the highlighted application. The iSight's indicator light will turn off.