You have to do this before you help Bozo out
1. After you solve the puzzle in the gadget shop and obtain the glasses, put the lens in the left frame and then combine the two frames together.
2. Go to the Dark Alley and put the glasses on the pile of rubbish that's to the right of the rebels hideout.
(there should be a bunch of eyes amongst the rubbish)
You'll get a cool reference when you do