What Is a Keyhole Bridge in Optics?
A keyhole bridge is a frame design where the bridge between the lenses resembles an old-fashioned keyhole. Instead of resting fully on the nose, it distributes weight on the sides of the nose for better comfort. The shape leaves space at the top of the bridge, reducing pressure on the nasal crest. This design suits people with narrower noses or higher bridges. It's both practical and stylish, found in many modern and vintage frame lines.
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