Possible Clues:

• That's one thing that's looking up as the fairies manage it
• Fairies cope — such may help little folk to have a vision
• Pose price mistakenly for part of a submarine
• Submarine's viewing tube
• Sub feature
• Submarine viewing device
• What improves vision, in the main?
• Overseeing helper?
• Optical instrument that provides a view of an otherwise obstructed field
• One sees what's up, in the main