proptometer

proptometer

 [pro-tom´ĕ-ter]
an instrument for measuring the degree of exophthalmos.

ex·oph·thal·mom·e·ter

(ek'sof-thal-mom'ĕ-tĕr),
An instrument to measure the distance between the anterior pole of the eye and a fixed reference point, often the zygomatic bone.
[exophthalmos + G. metron, measure]