Home training stereoscope

This would be sold to a patient to “exercise” his eyes at home. It is very much the same as the stereoscopes of the late 1800′s that were a source of parlor entertainment before TV took over. The card is from 1890 and is not original with this stereoscope. It says, “A Mexican Acequia with Bathers and Washerwomen
Copyright 1890 by J.F.Jarvis”