Kirby's Adventure - Kracko is a boss that is a spiked cloud with a single big eyeball in the middle. There are other one-eyed enemies in this game, too, like the things you get the fireball power from.

Kirby's Dream Land - Kracko.

Kirby's Dream Land 3 - Kracko again, and Dark Matter also has only one eyeball.

Kirby's Pinball Land - Kracko.

Ultima 6: The False Prophet - Cyclops enemies (and even a couple that aren't your enemies...)

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