Types of Bridges for Glasses
Everyone’s face is unique. When choosing a correct fit of a pair of eyeglass frames, the "bridge" measurement and type are key aspects to consider.
What is the bridge on glasses?
A bridge is the part of the frame between the lenses which sits on the nose. It supports the majority of the weight of the eyewear.
How should glasses sit on the nose fit?
They should fit securely on the bridge and don't pinch or leave indents. When you wiggle your head or bend over, they will not fall off or slide up and down. If the bridge is too small, your glasses will be too high on your nose and will pinch you. If the bridge is too large, the frames will slip down frequently.
What is bridge width?
Eyewear frame measurements contain three numbers in a format like 55-20-145. The middle number is the bridge width. It shows the distance between the lenses and ranges from 14 to 24. If your nose is narrow or your eyes are close, you’ll need a lower number, such as 14mm to 18mm. If your nose is wider or your eyes are positioned further apart, look for 18mm or higher.
What are different types of bridges?

Adjustable Nose Pads
They are the most versatile type of nose bridge. Usually found on metal frames, they can be widened or narrowed to accommodate various nose shapes and sizes. Moreover, they are particularly beneficial for minors whose nose bridges may not provide sufficient support to their frames.

Saddle Bridge
The saddle bridge is shaped like a horse's saddle. It spreads the weight of the frame across the top and the sides of the nose. This style works well for heavy glasses or those with sensitive noses.
Besides, saddle bridges create a more modern style and usually go around your nose with almost no gaps at the top. Because they have fewer moving components and are more likely to keep their fit, saddle bridges are noted for being low maintenance.

Keyhole Bridge
The keyhole bridge looks like an old-fashioned keyhole and is located on one side of the nose. One of the most popular styles in optical history is glasses with a keyhole-bridge design. The keyhole shape touches the two points of the nose bridge, eliminating pressure from the top of the nose.
It usually makes the nose look longer and wider which can change the eye-nose geometry, particularly if the frame color is dark.

Double Bridge
A double bridge adds a reinforcing bar over the top of the bridge.
Many facial shapes look good in frames with prominent browlines. Eyeglasses with a double bridge offer a fashionable flair and draw visual attention up toward the forehead. For faces with a diamond, oblong, or triangular shape, double bridge prescription glasses widen and add visual weight to the upper portion of the face, which can be appealing.

Low Bridge Fit
A low bridge fit contains a lower bridge, deeper nose pads, and longer temples. Low Bridge Fit frames are crafted for those with low nose bridges, wide faces, or high cheekbones.
A lower bridge and deeper nose pads allow the frame to sit higher and more comfortably on each side of the nose. It can prevent your glasses from falling or moving onto your cheekbones. Besides, the longer temples give extra room to reduce tension on the nose and cheeks while also ensuring proper adjustment behind the ears.