Aim: To explore and describe trends in the principal disorders/conditions ('cause') for severe sight impairment (SSI) (blind) and sight impairment (SI) ( partial sight) certi fication in children in England and Wales since 1999. Methods: We obtained certi fication data for SI and SSI from a national database for all individuals aged 16 years or less at the time of certi fication in England and Wales for the years 1999/2000 and for the years 2007/2008-2009/2010. Results: In total, there were 861 certifications in the year 1999/2000, rising to 1040 certifications in 2009/ 2010. The commonest single causes of SSI certification in 1999/2000 were cerebral visual impairment (23.2%) and optic nerve disorders (23.2%). The commonest single causes of SI certification in the same year comprised nystagmus (16.7%) and optic nerve disorders (15.5%). Cerebral visual impairment was the commonest single cause of SSI in children in England and Wales annually between 2007/2008 and 2009/2010 accounting for 21%-31% of certifications. The commonest causes of SI certification in 2009/2010 were congenital globe anomalies (18.4%) and retinal dystrophy (16.6%). The proportion of SI and SSI due to optic nerve disorders has decreased since 1999/2000. Conclusions: Our findings suggest that in England and Wales, cerebral visual impairment is now the commonest cause of paediatric SSI certification and hereditary retinal dystrophy and congenital globe anomalies are the commonest causes of SI certification.