I use to remember a time a few Mac OS X iterations ago when I shut down my lights in my room, the backlight keyboard within my MBP would light on automatically. This doesn't seem to be the case anymore with Mavericks or Yosemite (even previous versions) and this bothers me for some reason. To my knowledge there isn't a setting that can adjust this or bring this back, and I am aware that the brightness of the display and keyboard are adjusted accordingly to the light environment you find yourself in. (But only if the backlight is already on) Also there doesn't seem to be an application to do this or an official API that gives access to the sensor. What are your thoughts on this, do you miss the feature? Want it back? Maybe you guys have alternative solutions to this. It's not a major deal but it was pretty convenient and a cool magic trick.