Related Clues:

• Common prescription item
• It's under an eyebrow
• Magnifying glass, for one
• Magnifier, e.g
• One can refract light
• Many a Zeiss product
• Light beam refractor
• This might help you see French industrial town
• Camera's "eye"
• One of two in a basic telescope
• A simple microscope has one
• Glass fallen, smashed, though not entirely
• Perspective, figuratively
• Double-arc shape
• Camera option