Movies have always depicted biometric scanners. And it adds to the suspense aspect of the movies. Not many people realize, that Biometric Retina Scanner is already being used by government and its agencies, prisons and even the banking industry where identification is most crucial. 

However, since it almost always depicts carnage or removal of an eye or a finger. It puts biometric devices in a bad light.  What most do not know is, if it is separated from the rest of the body, the biometric device will no longer able to recognize it, as there will no more blood running thru our capillaries.