is it? when you answer the phone the part where you hear out of, to the left of that is like a camera looking thing, is it another camera? what is it??
its actually a motion/brightness sensor. when you put it to your face it knows because of that lil thing. when you have auto brightness on it adjusts depending on the lighting in the room. hope this helps.
It's a proximity sensor. It turns off the touchscreen and backlight when you're talking on the phone, so that you don't waste the battery or accidentally select something on the screen with your face