How do I choose between a saddle bridge and a keyhole bridge frame?

Consider the patient's nose shape. Saddle bridges work best on moderate-width noses with gentle slopes because they distribute weight evenly across a large area. Keyhole bridges are better for narrow or prominent nose bridges where a saddle would slide. If the patient needs maximum adjustability, choose a frame with adjustable nose pads instead.

Why do my patients get red marks from their nose pads?

Red marks usually indicate concentrated pressure, often from pads that are not angled correctly (only partial contact with the nose), pads that are too close together, or pads that are too small for the frame weight. Fix this by ensuring full-surface pad contact, widening the pad spread slightly, or switching to larger or softer silicone pads.

Can nose pad adjustments fix a frame that sits crooked?

Yes, in many cases. If the frame sits crooked due to nasal asymmetry (which is very common), you can adjust the pad heights independently, raising one side and lowering the other so the frame sits level despite the uneven nose surface. If the crookedness is caused by temple misalignment, temple adjustments are needed instead.

Bridge Fitting: Saddle, Keyhole, and Nose Pad Adjustments

Why Bridge Fitting Matters

The bridge is where the frame meets the nose, and it carries the majority of the frame's weight. Poor bridge fitting causes glasses to slide down, sit crooked, pinch the nose, or leave painful pressure marks. Because the nose shape varies dramatically between patients, bridge fitting is one of the most important and frequently adjusted aspects of dispensing.

A well-fitted bridge distributes weight evenly, keeps the frame at the correct height and angle, and feels comfortable enough that the patient forgets they are wearing glasses.

Saddle Bridge

A saddle bridge is a smooth, continuous curve that spans the nose without distinct pad components. The bridge rests across the crest of the nose and along both sides, distributing weight over a large surface area.

Advantages of saddle bridges:

Superior weight distribution because contact area is maximized
Comfortable for extended wear since pressure per square millimeter is lower
Ideal for heavier frames (thick acetate, large lenses) where concentrated pressure would be uncomfortable
Fewer adjustment options can be an advantage for patients who tend to misadjust their own glasses

Saddle bridges work best on noses with a moderate width and gentle slope. They are common on full plastic/acetate frames where the bridge is molded as part of the frame front.

Keyhole Bridge

A keyhole bridge contacts only the sides of the nose, leaving a visible gap at the crest. Viewed from the front, the opening resembles an old-fashioned keyhole shape.

Characteristics of keyhole bridges:

Better for narrow or prominent nose bridges where a saddle would slide or sit too high
More defined, classic aesthetic popular in vintage-style frames
Less surface contact means pressure is concentrated on two smaller areas
Frame sits lower on the face compared to a saddle bridge of the same size

When a patient has a flat or wide nasal bridge and their frame uses a keyhole design, the frame tends to sit too low or slide. Consider frames with a saddle bridge or adjustable nose pads for these patients.

Adjustable Nose Pads

Many metal and mixed-material frames use adjustable nose pads mounted on pad arms. This design offers the most fitting flexibility because you can independently adjust three parameters:

Pad Spread

Pad spread is the distance between the two nose pads. Adjusting this parameter affects how wide or narrow the frame sits on the nose:

Wider spread: Frame sits lower on the face; better for wider noses
Narrower spread: Frame sits higher on the face; better for narrow noses

Pad Angle (Splay)

Pad angle refers to how the pad surface is oriented relative to the side of the nose. Ideally, the entire pad surface should rest flush against the nose, maximizing contact area and minimizing point pressure.

If only the front edge of the pad contacts the nose, the pad is angled too far outward
If only the back edge contacts, the pad is angled too far inward
Full-surface contact distributes weight evenly and prevents the red marks patients commonly complain about

Pad Height (Vertical Position)

Adjusting the pad arm up or down changes the vertical position of the frame on the face. This directly affects where the optical centers sit relative to the pupils:

Raising the pads: Lifts the frame, moving optical centers up relative to the pupil
Lowering the pads: Drops the frame, moving optical centers down

Nose pad adjustments directly affect optical center height. After any pad adjustment, verify that the OC position still aligns with the patient's pupil center. This is especially critical for progressive lens wearers.

Nose Pad Materials

Material	Characteristics	Best For
Silicone	Soft, flexible, good grip, hypoallergenic	Sensitive skin, active wearers, heavy frames
PVC	Firmer, more rigid, durable, lower cost	Standard frames, patients who prefer a solid feel
Titanium	Hypoallergenic, very durable, smooth surface	Metal allergy patients, premium frames
Glass/Ceramic	Extremely durable, smooth, non-porous	Patients with skin reactions to polymer pads

Silicone pads are the most popular choice for their combination of comfort, grip, and hypoallergenic properties. They are available in various shapes (oval, round, D-shaped, teardrop) and sizes to match different nose anatomies.

Using the same pad shape and size for every patient. Nose pad fitting should be individualized based on nose width, bridge angle, and patient sensitivity. Larger pads distribute weight over more surface area, while smaller pads work better on narrow or very curved noses.

Troubleshooting Common Bridge Fitting Problems

Glasses slide down: Narrow the pad spread, increase pad grip (switch to silicone), or check that the pads are angled correctly
Red marks on nose: Widen the pad spread, ensure full-surface contact, switch to softer pads, or consider a frame with a saddle bridge
Frame sits crooked: Adjust pad heights independently so one side is higher or lower to compensate for nasal asymmetry
Frame too high or too low: Adjust pad height and verify OC alignment afterward

Key Takeaways

Saddle bridges distribute weight broadly and work well for wider noses and heavier frames
Keyhole bridges contact only the sides of the nose and suit narrow or prominent bridges
Adjustable nose pads offer three parameters: spread, angle, and height
Pad angle should allow full-surface contact with the nose to minimize pressure marks
Silicone pads are the most versatile for comfort and grip
Always verify optical center alignment after nose pad adjustments