Luminous ink contact lenses, the high-tech product for poker players, are one of the marked?deck readers that used to detect the luminous marked cards. By wear these lenses, the user can see the hidden marks (the number or letter indicating the value) on the back of the playing cards.
Why we can see the invisible marks after wearing the luminous ink contact lenses? Science tells us that some of the lights in nature are visible to human eyes, but some are not, such as the UV light and IR light. If people want to see the invisible light, they need the help of some tools, such as the IR camera.
Cheating marked cards are processed with luminous ink or IR ink, so, after the ink on cards back get dried, human eyes cannot see the marks anymore. Therefore, we need the help of poker lenses. Normally, they do not have a correction. If clients have shortsighted, we will ask his glasses prescription, and customize the contact lenses with diopters. The most important reason why people are willing to wear the luminous ink contact lenses is that it will not change the color of your eyes.