Perhaps the facial recognition written in undergraduate or even graduate classes does not handle physical disabilities (I think you're talking about non-standar

Perhaps the facial recognition written in undergraduate or even graduate classes does not handle physical disabilities (I think you're talking about non-standard faces, in this context.) Actual professional FR systems must handle conventional appearances, as well as individuals with birth defect deformities, significant facial scarring from injury such as fire, facial tattoos and jewelry, as well as outright attempts to disguise. When talking society population, the proportion of people with non-conventional appearances is significant. BTW, I'm lead engineer of a leading FR system.