Given the breakthrough of AlexNet in 2012 for the simpler problem of image classification, there was a flurry of research and publications in 2014 and 2015 on deep learning methods for face recognition. Capabilities quickly achieved near-human-level performance, then exceeded human-level performance on a standard face recognition dataset within a three year period, which is an astounding rate of improvement given the prior decades of effort.
Source: A Gentle Introduction to Deep Learning for Face Recognition