Pupil distance meter is a measuring instrument used in the process of optometry and glasses matching to measure the distance between the two pupils of the human eye.

The measurement principle of a pupil distance meter is that the visual target illuminated by a light source is imaged by an optical system at a specific working distance in front of the patient’s eyes. When the patient looks at the visual target, the visual axes of their left and right eyes intersect at this specific working distance. At this point, the light forms a reflective spot on the surface of the patient’s left and right corneas. The optometrist can simultaneously see the reading filament and these two reflective points through the eyepiece. After moving the left and right reading filaments to align with the reflective points of the patient’s left and right eyes, the patient’s pupil distance can be obtained on the display screen.

The pupillary distance calibration device is composed of an adjustable workbench with two-dimensional motion direction and three standard sleeves with nominal pupil distance values of 55mm, 65mm, and 75mm. The deviation between the actual center distance value and the theoretical center distance value of the three standard sleeves should be controlled within 0.1mm.

The pupillometer calibration device is equipped with two standard analog eyes with OD, which are used to simulate the reflection points of the target image observed from the patient’s pupil under working conditions.