Visual disturbances may take many forms but there are some important variants to recognise as follows:
1. Ameurosis fugax is a form of retinal TIA and is discussed separately.
2. Non specific, acute onset visual symptoms are commonly due hypoglycaemia.
3. Sudden onset, monocular, loss of all or part of vision, especially if described as "like a black area in the middle" and which does not reverse is usually due to a vitreous haemorrhage.
4. Homonymous field defects of acute onset, especially if associated with neglect (although of course the patient will not complain of the latter), are likely to be due to posterior circulation TIA/stroke.