Bifocals Used to Cheat Poker
Article from the Lincoln Journal in 1894 explaining how poker cheats read marked cards with specially designed glasses
Marked Cards 1894
The prize of all poker cheating devices is marked cards. Why, me lads, they are painting cards now that the lad who is "on" can read them on a block but the guy that is "not on" - not in a million years could he get "on".
Within the past few years great improvements have been made in this branch of "advantage playing" Cards are sold, apparently of ordinary patterns, but in reality marked microscopically. Even a gambler who is throughly conversant with ordinary marked cards can detect nothing wrong with these. But with them are sold eyeglasses, the lenses of which are divided into two portions. The upper part is clear glass, but the lower section of each is a magnifying glass of great power. The possessor usually has another pair of glasses, apparently similar, but in reality both sections of the latter are clear glass, and these he wears constantly. But when he sits down to a game he exchanges for the other pair, and when he deals, looking down at the cards through the lower halves of the lenses, he reads the cards as readily as if they were dealt face up.
Talk about your cold deck and stripers and so on, but they are not in it with the painted cards. So take High Card's advice and don't play cards with strangers. - Cincinnati Enquirer