Related Clues:

• Minor annoyance
• Film flaw
• Tiny aperture
• It's hard to see through
• A poster may have one
• Small aperture
• Tiny opening
• It admits very little light
• Camera obscura feature
• Flask flaw
• Balloon flaw
• A small annoyance or sting
• Tiny injury
• Source of a slow leak, perhaps
• Tiny irritation