"Leaning against the crude workbench as if it were a crutch, half in shadow, was his mentor from Black Mesa and, before that, MIL Dr. Kleiner looked even more weathered than Barney. He wore an eyepatch over his left eye, and that side of his face was a mass of twisted scar tissue." -Marc Laidlaw's description of Dr Kleiner from the short story "Old Friends." Yes, wrong eye. Will fix it at some point.
And yes, you can download him here: gamebanana.com/mods/324151