orthometer

orthometer

 [or-thom´ĕ-ter] an instrument for determining the relative protrusion of the eyeballs.

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. Synonym(s): orthometer, proptometer, statometer [exophthalmos + G. metron, measure]