Eyes · Front photo

Pupil distance

IPD

The number used for fitting glasses. The iris scale is good to a few percent, so read it as approximate.

How it's measured

Distance between the pupil centres in millimetres. The scale comes from the iris, which is close to 11.7 mm across in adults, so the value only appears when the detector measured the irises.

Reference range

Male reference

61–68 mm

Female reference

59–66 mm

Source: About one standard deviation around the adult means of 64.7 mm (men) and 62.3 mm (women) in Dodgson NA. Variation and extrema of human interpupillary distance. Proc SPIE 2004;5291:36-46.

In the score

Shown for information. It isn't part of the score.

What changes it

• Camera distance changes it: close-up selfies enlarge the middle of the face. Shoot from about 1.5 m and zoom in.

One number, one feature

One measurement describes one detail in one photo. Pose, lens and expression move it, and every reference range is an average from limited samples.

More background: Eye separation ratio (ESR).