US Patent 9261959 Input detection

Exemplary methods and systems provide for eye-tracking. An exemplary method may involve: causing a projection of a beam of light onto an eye and receiving data regarding a reflection of light from the beam of light off of the eye. The method further includes correlating a pupil of the eye with a darkest region from the data. The darkest region comprises a region that is darker relative to other regions of the reflection data. Once the pupil has been correlated and the pupil location is known, the method includes executing instructions to follow the pupil as the eye moves.