14 DAY TRIAL // A developer named Moshen Chan has discovered that Macintosh computers running OS X Mavericks will delay the sleep timer whenever the system senses movement.
At first, it was thought that Mavericks used the iSight camera to watch the user move about, but it was later revealed that the OS uses the ambient light sensor to track changes in lighting.
Needless to point out, panic broke out for a little while until it was confirmed that Mavericks doesn’t go about turning on your iSight camera without your permission.
All this function does is interpret any changes in light as movement, resetting the idle timer which tells your computer to go into Sleep mode.
To make one matter clear, Apple usually doesn’t disclose these features because they are too insignificant to deserve a line of text in the release notes. Imagine if every such tweak was mentioned. You’d end up with a changelog the size of the iTunes EULA.