Blue-tinted spectacles (as they were called back in the day) afforded the wearer a huge advantage over all other card players at the table because with the use of phosphorescent ink he could mark a deck of cards and with the use of the special glasses he could view the markings while his opponents could not.
The illustration below comes from the K.C. Card Co., Blue Book Number 436, catalog, page 22. Also listed on that page are; Luminous Glasses or Visor, Luminous Material, Luminous Ink and Luminous Daub.
In the book, "Gamblers of The Old West", page 120 an entire page is devoted to "Cheater Glasses" and repeats the information already covered on this page.