optotype

German-born optometrist George Mayerle developed a rather comprehensive and inclusive eye chart whilst practising in San Francisco that reflected the diversity of his adopted home.
The radiant dials above test for astigmatism and the bars at the bottom can be used to reveal colour-blindness. Different scripts are represented as well as pictorial characters and geometric symbols for the pre-literate and is nearly contemporaneous with the Snellen table that we’re probably best acquainted with. Learn more about this striking diagnostic tool at Public Domain Review at the link above and find out how to purchase a copy of your own.