Concept art by Giger - the facehugger has an eye. Alan Dean Foster describes the facehugger (on Kane's face) the same way in the Alien novelisation:
https://theprotomorph.tumblr.com/post/159891053632
Indeed there was some very interesting alternative Face Fugger Designs, i would have liked a Prequel to had touched upon some of the other designs... much like how the Mural had TWO of them.
I would have loved to had seen more of these.
R.I.P Sox 01/01/2006 - 11/10/2017