[Ophthamology] Snellen, H. Scala Tipographica, per mesurare il visus

Utrecht, P.W. van de Weijer, 1862. 1st ed., Italian version. 6 p., 19 plates w. visual acuity tests, of which 1 col. and 2 fold. depicting the Snellen chart, orig. paper wr.

Spine completely worn, quires loosening. Rare work which contains the first publication of the Snellen chart, which for over a century served as the standard for determining visual acuity and is still commonly used today.