Legal blindness, as defined in USA Note: The table below gives a classification of severity of visual impairment recommended by a WHO Study Group on the Prevention of Blindness, Geneva, 6-10 November 1972.The term 'low vision' in category H54 comprises categories 1 and 2 of the table, the term 'blindness' categories 3, 4 and 5, and the term 'unqualified visual loss' category 9.If the extent of the visual field is taken into account, patients with a field no greater than 10 but greater than 5 around central fixation should be placed in category 3 and patients with a field no greater than 5 around central fixation should be placed in category 4, even if the central acuity is not impaired. Inclusion term(s):Blindness NOS according to USA definition