This Antique Snellen's Standard Test-Types Vision Test Cards appears to have been produced for use by the New York Central System for checking the eyesight of their prospective and current railway employees. Included in this set is the following: Directions for use The American Railway Association Standard Reading Card Certificate of Vision, Color Perception, and Hearing (last one on original pad) 15 foot cards 20 foot cards 30 foot cards 40 foot cards 50 foot cards 70 foot cards Each of the cards includes a hole, typically with a grommet in it for hanging at the prescribed distance from the person being examined. The best estimate I can get on age is sometime between 1900-1930. The cards are a nice weight card stock. The envelope included is basically just a remnant to help complete the set. Please review the photos and email me with any questions BEFORE bidding, purchasing, or making an offer. I try to respond as quickly as possible, but please allow up to 24 hours for a response. If you purchase more than one item, let me invoice you with an updated total and combined shipping. I try and include multiple shipping options, so be sure and look at all of them for your least expensive options. See my other listings for more of my items available for sale. For items with free shipping, I reserve the right to change the shipping method while committing to treating your purchase with respect.