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The California Institute of Technology has developed a lens that makes eye
operations more likely to succeed (WO 00/41650). In a cataract operation,
surgeons replace the clouded lens with an implant whose optical power has to be
just right, as it cannot be adjusted later. This leaves half of all patients
needing glasses. The new lens is made from semi-fluid polymer, mixed with a
light-sensitive monomer with a lower refractive index. After surgery, shining a
bright light onto the centre of the implant polymerises the monomer, increasing
its refractive index by the required amount.