Attention is aroused however when the patient is found to collide with pieces of furniture, to fall over objects, and to experience difficulty in finding his way around. They may try to walk through a wall or through a closed door on his way from one room to another. Suspicion is still further alerted when they begin to describe people and objects around them which, as a matter of fact, are not there at all. Thus we have the twin symptoms of anosognosia (or lack of awareness of defect) and confabulation, the latter affecting both speech and behaviour. Anton syndrome may be thought of ideally as the opposite of blindsight, blindsight occurring when part of the visual field is not consciously experienced, but some reliable perception does in fact occur. Causes
Why patients with Anton syndrome deny their blindness is unknown, although there are many theories. One hypothesis is that damage to the visual cortex results in the inability to communicate with the speech-language areas of the brain. Visual imagery is received but cannot be interpreted; the speech centers of the brain confabulate a response.Patients have also reported visual anosognosia after experiencing ischemic vascular cerebral disease. A 96-year-old man, who was admitted to an emergency department complaining of a severe headache and sudden loss of vision, was discovered to have had a posterior cerebral artery thrombosis with consequent loss of vision. He adamantly claimed he was able to see despite an ophthalmologic exam proving otherwise.
Anton syndrome, also known as Antons blindness and visual anosognosia, is a rare symptom of brain damage occurring in the occipital lobe. Those who have it are cortically blind, but affirm, often quite adamantly and in the face of clear evidence of their blindness, that they are capable of seeing. Failing to accept being blind, people with Anton syndrome dismiss evidence of their condition and employ confabulation to fill in the missing sensory input. It is named after the neurologist Gabriel Anton. Only 28 cases have been published.Although sometimes the two terms are used as synonymous, Anton syndrome must not be confused with Anton–Babinski syndrome which is characterised clinically by contralateral sensory neglect, anosognosia with associated affective indifference toward the condition (anosodiaphoria), construction and dressing apraxia. Anton–Babinski syndrome is the right-hemisphere equivalent of Gerstmann syndrome and it is due to non-dominant inferior parietal lobule damage. Presentation
Anton syndrome is mostly seen following a stroke, but may also be seen after head injury. Neurologist Macdonald Critchley describes it thus:

The sudden development of bilateral occipital dysfunction is likely to produce transient physical and psychological effects in which mental confusion may be prominent. It may be some days before the relatives, or the nursing staff, stumble onto the fact that the patient has actually become sightless. This is not only because the patient ordinarily does not volunteer the information that they have become blind, but he furthermore misleads his entourage by behaving and talking as though they were sighted.