1. School of Applied Sciences, University of Brighton, Brighton BN2 4GJ, U.K.
2. Department of Materials Science and Engineering and A. J. Drexel Nanomaterials Institute, Drexel University, Philadelphia, Pennsylvania 19104, United States
3. Rayner Intraocular Lenses Limited, The Ridley Innovation Centre, Worthing BN14 8AQ, U.K.