blemmatrope

blemmatrope

(ˈblɛmətrəʊp)

[f. Gr. βλέµµα look, glance, f. βλέπειν to look + τρόπος turning, f. τρέπειν to turn.]

‘An apparatus for illustrating the various positions of the eye’ (Catal. Sci. Appar. S. Kensington, 1876).