Six encounters another Eye after entering a room with a rolling janitor's bucket, which the Eye would focus on while it was moving. Later, after entering the prison, Six encounters her first Eye, which is surveying a room filled with children that had been turned to statues.
In the first Little Nightmares, an Eye can first be seen above an entrance that the Janitor entered during the introduction to the Prison. Although there are numerous eye symbols found throughout the Maw, these Eyes generally refer to artificial devices which were likely designed to prevent prisoners from escaping and intruders from entering, having a similar mechanism to a security camera.