- Correspondence to: Philip B Morgan Department of Optometry, The University of Manchester, PO Box 88, Manchester M60 1QD, UK;
- Accepted August 29, 2004
- First published March 17, 2005.
If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.