Differences in Pupilometer?

[sdgibbs]

So pupilometers like this

http://i.ebayimg.com/00/s/MTAwMVgxMDAx/z/Tr8AAOxyOalTaF6k/$_57.JPG

seem to be about a quarter of the price as these

http://i.ebayimg.com/00/s/MTYwMFgxNjAw/z/-0EAAOxyhodRznZF/$(KGrHqN,!qcFGlEjIVVeBRznZEv7Hw~~60_57.JPG

Are the simply cheaper to produce, or are they actually bad in some way? I only have experience with the second type how is the first?

Thank you as always!

[MakeOptics]

So pupilometers like this

http://i.ebayimg.com/00/s/MTAwMVgxMDAx/z/Tr8AAOxyOalTaF6k/$_57.JPG

seem to be about a quarter of the price as these

http://i.ebayimg.com/00/s/MTYwMFgxNjAw/z/-0EAAOxyhodRznZF/$(KGrHqN,!qcFGlEjIVVeBRznZEv7Hw~~60_57.JPG

Are the simply cheaper to produce, or are they actually bad in some way? I only have experience with the second type how is the first?

Thank you as always!

The first one is a novelty item, more a fancy ruler. The second has a dial for working distance which slides a large inner lens (+) to truly simulate working distance. The second can provide a more accurate measure user permitted of course.

[sharpstick777]

A cheap pupilometer is the most expensive money you will ever save. Took over a huge practice once with a very high redo rate, traced it to bad pupilometers. I estimate the loss of unnecessary remakes at about $3400 a month by comparing redos before and after getting new and high quality pupilometers.

A PD ruler is probably better than a cheap pupliometer, saving you even more money if that is what your after.