Possible Clues:

• Parts of the eyes
• They'll pick up light Greek wine, keeping the second to last
• Targets of some scanners
• Optic nerves connect to them
• Eye parts with cones
• Anatomical analogs to camera film
• Eye parts with rods and cones
• Eye parts that receive images
• Holders of eyes' rods and cones
• They'll see to it that one can have them in tears