Blindness is defined as the lack or loss of ability to see. A person is registered as blind if they have a corrected acuity of < 3/60 in the better eye.
Types of blindness include:
- rapid onset, with bilateral loss of sight
- gradual onset, with bilateral loss of sight
- rapid onset, with unilateral loss of sight
- gradual onset, with unilateral loss of site
Any patient with sudden painless loss of vision requires specialist review unless the cause of visual loss is unequivocally migraine.