Introduction: The pupil dot diameter of this contact lenses is 11mm, so it will not change the user's pupil color and perform perfectly to see the marked ink. Pupil diameter: 11mm Working hours each time: about 8 hours Optional Accessories: 1.Luminous poker playing cards 2.Marked rummy cards 3.Marked Chinese Mahjong Advantage: 1.More safety than perspective glasses 2.The easiest way to cheat in poker game 3.High quality to see marked cards 4.Can use for all kinds of poker game. Tips for using the contact lenses: 1.The best suitable situation is under the white light, especially the energy-saving light. 2.Please make sure to wash your hands clearly before wear the contact lenses in case of infecting your eyes. 3.Before playing the poker games with contact lenses, the user have to wear the contact lenses half or several hours for adapting.