Using a UVC-compatible webcam (I believe this is what you mean with “vision sensor”) and OpenCV should do the job. You can check a list of compatible webcams following this link http://www.ideasonboard.org/uvc/.
OpenCV already have some tutorials on this subject that you might want to check, http://docs.opencv.org/2.4/modules/contrib/doc/facerec/facerec_tutorial.html.
There are also some videos from Intel’s Maker Garage, specifically talking about Facial Recognition, you can find them here http://www.intel.com/content/www/us/en/do-it-yourself/garage-content/garage-facial-recognition-video.html. There’s a lot of information in the Edison Community and around the web that you should check.