When someone finds a wad of something and then sticks it in their eyeball thinking that will help with their vision.
I just stuck a wad of wood in my eyeball and now I have wad eye. I'm so fucking stupid, why on earth did I do that... NOW I HAVE SPLINTERS IN MY MOTHERFUCKING EYEBALLS! GOD FUCKING DAMN IT!
Occurs after having played various mods of a video game for a long duration of time that reuse the same assets; making you think, after a period of time, that you've played another unrelated, separate mod already, when you haven't.
"I could've sworn I played this already, no?", "I'm developing The "Doom Wad" Effect"