The Third Edition sees a new team of authors who have kept very much to this priniciple in their nevertheless thorough revision of the book. Whilst there are no new chapters as such, the immediate impact of the revision is in the improved page layout with increased use of diagrams and flowcharts. There are new sections on feigned visual loss in adults and children, the management of residual defects and the section on botulinum toxin treatment in chapter 8 will be re-written to take account of the great advances in this form of treatment.