These contact lenses work with a poker deck marked in X-ray. These contact lenses are specially designed to be invisible to other players. These contact lenses are very helpful for cheating in the poker game.
Toric contact lenses are not made for a spherical (more like a baseball) cornea. Instead, they are designed for astigmatic (more like a torus or, more commonly, like a football) corneas. The specialized design of toric contacts creates different focusing powers vertically and horizontally across the lens. This is why your toric contact lens prescription will have numbers in the “SPH,” “CYL,” and “Axis” columns.
These contacts are designed to correct astigmatism and other refractive errors such as nearsightedness and farsightedness. In order to achieve these multiple focuses in one lens, the design of toric lenses is a little more complicated than regular contact lenses. They are also heavier than other contact lenses to ensure that they stay in place and don’t shift as you blink.
PSI’s X ray lenses are based upon existing technologies, but had to be developed due to the unique physics governing X ray light. Unlike visible light that can be split into its spectral colours by passing through different materials, X rays are absorbed and cannot be reversed. This meant that the first part of the achromatic lens had to be created with established nanolithography methods while the second – the refractive structure – had to be created using 3D printing on the micrometer scale.