Paracetamol is considered the safest of the over-the-counter pain killers to use whilst pregnant so consequently it is the most widely used. Research suggests that approximately 60% of women in Northern Europe reported taking paracetamol during pregnancy and as it has been classified as safe for use during pregnancy there is an assumption that there are no harmful effects to the baby. However, recently some studies have suggested that the risk of asthma, autism and behavioural problems increases where paracetamol has been taken by the mother during pregnancy. Other preliminary studies have shown that there are associations between visual impairments and parent-reported behavioural difficulties in the child. We therefore would like to determine whether paracetamol use may lead to impairments in the child’s visual development which could in turn contribute to the behavioural disturbances.