Prosthetic eye lens. Dwarfed by an American dime coin, this micro-thin lens (at centre, blue) is the first diffractive eye lens to be designed that corrects for colour distortion. It is 5-10 microns thick, 4 millimetres in diameter, consisting of a lightweight plastic polyimide. Conventional lens implants rely on thickness for their power, and have a tendency to split colour. The micro-thin lens solves these drawbacks. Grooves etched on its surface focus colours on the same spot within the eye; while its size and flexibility would make it simpler to implant. This ongoing research may have widespread application in cataract surgery.