Snellen Vision Testing Cards Set for Railway, Marine and School Exams, Early 20th C. name tags This tall double opening vase

This tall double opening vase

and all the sliding parts slide smoothly

I of course like to imagine this set was used by a student at the Bauhaus

) Nicely graphic in red

but completely blank back

Snellen Vision Testing Cards Set for Railway, Marine and School Exams, Early 20th C. name tags This tall double opening vaseFound in their original envelop, with Millar and Wel_ (?) Opticians on, Boston stickeron the face and instruction card still inside, this appears to be a complete, or nearly so, set of early 20th c. Snellen vision testing cards. Nineteen cards total, plus instruction card, with three of the cards showing railway signals to be read at a distance of 20 feet as these were commonly used for testing the vision of train conductors railway workers. Included: