12.1 Background

Most squints start in childhood and result from abnormalities in the development of the brain mechanisms controlling eye movements and binocular vision. These mechanisms can break down in a number of different ways and at different ages resulting in different types of squint. Others result from weakness of, or damage to, the muscles moving the eyes or the nerves controlling them. These latter types of squint are more common in adults. In children under seven the vision in one eye may deteriorate because the abnormal visual experience resulting from misalignment of the eyes, differences in focus between the eyes or other abnormal visual experience may lead to changes in visual connections in the brain and to poor vision in that eye known as amblyopia or "lazy eye".

Squint and amblyopia are common conditions, affecting 3 to 5% of children. Both have a lifelong impact on visual function and appearance, with consequences for education, career choice, employment, self-esteem and personal relations. The aim of research is to find ways of preventing or minimise the impact of these conditions. This will have lifelong benefits for the patient and society.

   12.2 Research Potential