Berzerk - The robots have one eye that spins around their head.

Breath of Fire - Tronk and Stool enemies have only one eye. (And that "stool" is short for "toadstool". *ahem*)

Aidyn Chronicles - Cyclops enemies.

The Guardian Legend - The Fleepa boss has only one big eye. So do the Optomon bosses.

Zanac - Some of the minibosses are these shielded ships with one eye in the middle. There are smaller enemies like those, as well.

I Crawl and 1000
My site - Flying Omelette's Kitchen
My ezboard - Flying Omelette's Kitchen
MIDI of the Moment - Castlevania 2 - Bloody Tears
"I hear mariachi static on my radio
And the tubes they glow in the dark
And I'm there with you in Ensenada
And I'm here in Echo Park" - Warren Zevon