Actual PD does not change, but the bridge, inner rims and frame size create new visual reference lines around the eyes, while powered lenses can separately magnify or minify the eye area.
01 · CENTER SPACE
The bridge and inner rims create new visual boundaries between the eyes
When glasses are worn, a bridge and two inner rim edges are added between and beside the eyes.
The spacing, thickness and contrast of these lines can make the center area feel more connected or more separated.
The direction is design-dependent, so a narrow bridge does not always make the eyes look closer together.
02 · INNER RIM
Inner-rim position and thickness affect relative pupil placement
A thick, high-contrast inner rim creates a stronger boundary near the eyes.
This can emphasize how far inward or outward the pupils appear within the lens openings.
It is a relative visual effect, not a change in actual PD.
03 · FRAME SIZE
In a larger frame, the eyes can appear more inward relative to the lens openings
As the frame center distance increases, the pupils of a wearer with the same PD can appear relatively farther inward within the lenses.
This alone does not make the frame wrong; optical reference points are still centered to monocular PD and the prescription.
An extreme mismatch can also increase lens decentration and required blank diameter.
04 · SMALL FRAME
A smaller frame can change the relative position in the opposite direction
With smaller lens openings and a smaller frame center distance, the pupils may appear closer to the geometric centers or farther outward within the openings.
That is why the same face can look different with different frame sizes.
The actual PD itself remains unchanged.
05 · OPTICAL EFFECT
Powered lenses create a separate magnification effect
Minus lenses generally make the eyes appear smaller, while plus lenses can make them appear larger.
The amount depends not only on power but also on vertex distance and lens form or design.
Separate the visual effect of the frame from the optical effect of the lenses.
SOLUTION GUIDE
Solutions at a glance
Compare the bridge, inner rims and total frame size.
Check monocular PD relative to frame center distance.
Consider lens magnification or minification separately from frame design.
GLANOS FITTING CHECK
GLANOS fitting check order
- Frame
Look at the visual boundaries created by the bridge and inner rims. - Eye position
Separate relative position in the frame from actual monocular PD. - Lenses
Check magnification or minification from the prescription. - Fit
First make sure the frame is in a stable wearing position.
CAUTION
This does not mean the eyes must sit at the geometric center of the lenses
The required lens reference points are positioned according to monocular PD, prescription and lens design. Visual position within the frame and optical centration are different concepts.
GLANOS EYEWEAR
There is a reason glasses feel uncomfortable.
eye spacing · PD · frame width · bridge · myopia glasses · hyperopia glasses · eyewear design