Eyes stay completely stationary and track Isaac quickly as he moves, firing a laser similar to that of Technology when they get the chance to do so.
Up to three eyes will appear in a room, often near the center. They occasionally spawn in the corners, making them difficult to kill without taking damage.
It is recommended to strafe around them while firing tears, as their lasers won't hit Isaac unless he stops moving for a short while.
A variant of Eyes, known as the Bloodshot Eye, commonly appears in Sheol, and can replace regular Eyes in The Womb. If encounted in The womb, it will be counted as a champion, and will drop a Pick Up upon death. Instead of firing a Technology laser at Isaac, they will instead fire a Brimstone laser. This laser hits much more often, thus making it much more dangerous, especially in groups.
Trap Eyes were introduced in Rebirth. This one works more like trap. It shares same visuals as Bloodshot Eye, although it constantly shoots Technology 2 alike beam, and spins clockwise. Beam damages not only player, but enemies as well. Room with Trap Eye features few blocks, which can be used as cover, since the beam does not go through. Once room is cleared, trap disactivates.
- The Brimstone lasers fired by Bloodshot Eyes usually do not reach the end of the room, and thus appear to be cut. This is only a graphical glitch, and Isaac can still be hurt by the lasers even if they don't reach him.
- Eyes are a reference to the Beamos, originating from The Legend of Zelda: A Link to the Past. Both normally are placed in the middle of a room from where they follow the player's movement to shoot them if they stand still for too long.
- Eyes are also similar to an enemy from Super Meat Boy that behaves the same way, following the player and shooting lasers.