The same marked bridge number does not describe the full three-dimensional contact geometry of the bridge, so differences in height, inner curvature, thickness and frame position can produce very different comfort.
01 · BRIDGE NUMBER
The number does not describe the whole bridge shape
The bridge size in a conventional frame marking is generally based on the boxing-system DBL, or distance between lenses.
That one number does not tell you the actual internal width, height, curvature or contact depth where the nose meets the frame.
The same marked number can therefore produce a different nose fit.
02 · BRIDGE HEIGHT
Bridge height and position can differ even at the same marked size
One frame may place the internal bridge contact higher while another places it lower.
That changes where the frame sits on the nose and the position of the lenses in front of the eyes.
03 · INNER CURVE
The inner nose-contact surface can be completely different
Differences in roundness, flatness and side slope change the true contact area.
One frame may support broadly while another touches mainly at an edge.
04 · FRAME THICKNESS
Bridge and front thickness also affect facial clearance
The thickness and projection of the inner bridge, along with front thickness and lens placement, can change the lens-to-face distance.
This is one reason lash or cheek interference can differ despite the same bridge number.
05 · FRAME POSITION
Temple geometry and front tilt change the result too
Even with similar bridge geometry, temple direction, pantoscopic tilt and overall front alignment can change the final wearing position.
The completed fit matters more than the bridge number alone.
SOLUTION GUIDE
Solutions at a glance
Check where the frame actually sits on the nose.
Check how it matches the nose slope.
Look for edge pressure.
Check lens-to-face distance.
Check lens position and overall balance.
GLANOS FITTING CHECK
GLANOS fitting check order
- Front
Check frame alignment. - Bridge
Judge actual contact rather than the printed number. - Width
Check side support. - Temple bend
Finalize the wearing position.
CAUTION
Do not buy a different model online simply because the bridge number matches your old glasses
Different brands and models can have very different internal bridge shapes and frame positions despite the same marking. Review detailed measurements and likely wearing geometry when possible.
GLANOS EYEWEAR
There is a reason glasses feel uncomfortable.
bridge size · plastic glasses · frame size · acetate · frame selection · eyewear fitting