Related Clues:

• There may be a shadow on it
• Cap for a pupil
• Optical shutter
• Movable sight screen
• Shutter usually closed at night
• I heard hat serves as a protective covering
• Contemplate pool, mainly closed at night
• If it's closed, you can't see priest you once introduced to daughter
• Winking membrane
• Cover for organ of sight
• It blinks
• The blinking thing!
• It's often closed for the night
• Egyptian leader distributed yield from pupil's cover
• Open's one's eyes perhaps to me, say, on cover