Is it a kind of contact lens? Is there more information about this (making-of, documentaries, etc.)?
Sim, eles usaram lentes de contato espelhadas (refletindo a luz).
Deste versão editada de Shooting Westworld por Michael Crichton
Three problems were especially tricky. One was the robot eyes. I wanted eyes that looked only slightly unreal, not strikingly bizarre. After some experimentation, we settled on eighty percent reflectant mirrored contact lenses, which gave us flexibility to control the "kick" by lighting. They also had the virtue of permitting the actors to see through them.
Também a partir de Artigo Oohlo,
You might notice (especially in the header picture) a particular glow in the Gunslinger’s eyes (Cylon red spine, anyone?). That is no digital effect; Brynner wore mirrored (light reflecting) contact lenses.