Visual attention as an important visual function: an outline of manifestations, diagnosis and management of impaired visual attention.

Impaired visual attention is a common manifestation of cerebral dysfunction. In adults, closed head trauma, cerebral microvascular ischaemia and dementia are common causes. In children, aetiologies include periventricular leukomalacia, hydrocephalus, hypoxic ischaemic encephalopathy and brain damage caused by hypoglycaemia. The resultant visual disability can be profound even when visual acuities are unaffected, and can cause significant disability in the execution of daily activities. This can prompt consultation with an eye care specialist. Patients complain of poor vision, difficulty in identifying someone in a group, or finding an object on a patterned background or among other objects, but a thorough examination often does not reveal the clinical basis for these complaints. The diagnosis of attentional dysfunction is also easily missed because at present it can only be recognised on the basis of adequate history taking from both the patient and close relatives and friends. The Useful Field of View test facilitates the detection and quantification of this disorder. Management includes the implementation of strategies that diminish background pattern and foreground clutter.