Can visual function be restored in patients with homonymous hemianopia?

It can be argued that vision is the major sensory input into the human brain, by virtue of the fact that about half of all aVerent fibres projecting to the brain are from the eye and by the sophistication of the neural systems controlling visual processing. Brain damage disrupts these complicated processes, resulting in severe visual impairments including hemianopia. Patients with hemianopia complain mainly of diYculties with reading and scanning scenes fast enough to make sense of things as a whole. Consequently, they fail to notice relevant objects or avoid obstacles on their aVected side and may collide with approaching people or cars. This has far reaching repercussions on their vocational and private lives. A small group are unaware of their defects until they are picked up on routine ophthalmic examination. Given the relative importance of vision as a sense, the treatment of hemianopia should assume a priority role for neurological rehabilitation programmes. In clinical practice, however, this has not been the case.