The WHO estimates that 19 million children aged 15 years or younger are visually impaired. Of these, 1.4 million are irreversibly blind and need visual rehabilitation interventions for full psychological and personal development. The remainder have visual problems that could be prevented or treated. Identifying children with visual problems early in life so that they can benefit from medical and optical interventions remains a key challenge for most child eye health programmes. Reports from various low-and middle-income countries indicate that the age of children undergoing operation for cataract is frequently too high to achieve maximum benefit.