This kind of contact leneses is suitable all the people with different eyes color.Course after wearing XF contact lenses ,it will appear your eyes color so it is hard to be found by others. How to cheat in poker game?And how to know the playing card's suit and number? Don't worry ,XF UV contact lenses is a good choice to help you cheat at Texas holdem ,Omaha games ,report cards one by one.Once you wear XF UV contact lense ,you will see the suit and number clearly of the XF invisible ink marked cards but other players can not see. Tips for using XF fantastic contact leneses: 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 our contact lenses in case of infecting your eyes. 3. Before playing the poker games with contact lenses, it is better the player wear the contact lenses about several hours for adapting.