Possible Clues:

• Pair of glasses that clip on the nose, with no side-pieces
• Aid to lookout on the bridge
• Foreseeing, perhaps, that one knows that's where they're pinching in France, by the sound of it
• Glasses clipped on to the nose
• Glasses fixed to nose
• Clip-on glasses
• Pair of eyeglasses with a nose-clip
• Sort of spectacles not much seen nowadays
• Eyeglasses suitable for van Gogh, ultimately?
• Accessory for Teddy Roosevelt