Huanyu Optical Digital Pupilometer 44-83mm Pupillometers Button Control Pupil Meters LCD PD Meter with Auto Sleep & Shut Down CE Approved (LY-9S)

We were a little concerned about purchasing an all digital Pd meter but took a chance since Amazon has a generous return policy. Received our unit in two days and quickly tested its calibration which was perfect. Like having an instrument with no moving parts to jam. Like having numerous distances from which to test. Would like the distance icons at the bottom of the screen to be a little bigger for easier viewing but otherwise the instrument is working well for our clinic.

TL;DR: Stick with the traditional design with manual sliders and a rotary optical knob.This PD meter uses vertical lines on a liquid crystal panel, controlled by a button, rather than vertical indicators on manual sliders. It's a neat concept which in theory would allow for better repeatability of measurements. In practice, they have removed necessary functionality in order to make this work.The distance selector calculates (estimates) every PD value other than at infinity, so it is no better than just guessing with conventional methods (subtracting 1.5mm, for example). The only optical measurement is taken at infinity.The monocular PD measurement (covering one eye and measuring the other) is useless, since there is no physical cover over the window. The liquid crystal panel only blocks light in one direction, and that direction is toward the technician, so the patient still sees the image through both eyes.The clip that retains the folding plastic panel on the underside of the device is very flimsy, and mine arrived broken.

It works, but its cheap and so is the price I guess. Should I have expected more... yes. It works, but cheaply constructed, wouldn't buy this for a busy office.

Worked perfectly. Used this to order my glasses from Zenni and they are the best aligned lenses I have owned. Requires another person to use but is very accurate.

Works well for what it’s supposed to do. Easy to ise

Did not work. DOA. Tried to contact Huanyu but not able to. We were too. busy to return on time.

Works very nicely

Excellent product