3D Glasses/Optimizer Goggles
In the instruction manual that came with the game Sly 3 Honor Among Thieves, there was a page with the different pieces of the 3D glasses that could be cut out, this page is included below. During specified missions throughout the game, the player could wear the 3D glasses, thus making the game 3D. In the game, Bentley refers to the 3D glasses as 3D Optimizer Goggles, and Sly claims they are stylish and functional. You could also obtain the 3D glasses for free if Sucker Punch messes up your order, they will send them to you, as I have experienced first hand. In The Sly Collection, the 3D glasses no longer work.