H54.8: Legal blindness, as defined in USA inclusionTerm Blindness NOS according to USA definition excludes1 legal blindness with specification of impairment level (H54.0-H54.7) notes 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. visualImpairment visCategory Category of visual impairment visRange Visual acuity with best possible correction visMax Maximum less than: visMin Minimum equal to or better than: visCategory 1 visRange visMax 6/18 visMin 6/60 visRange visMax 3/10(0.3) visMin 1/10(0.1) visRange visMax 20/70 visMin 20/200 visCategory 2 visRange visMax 6/60 visMin 3/60 visRange visMax 1/10(0.1) visMin 1/20(0.05) visRange visMax 20/200 visMin 20/400 visCategory 3 visRange visMax 3/60 visMin 1/60(finger counting at one meter) visRange visMax 1/20(0.05) visMin 1/50(0.02) visRange visMax 20/400 visMin 5/300(20/1200) visCategory 4 visRange visMax 1/60(finger counting at one meter) visMin Light perception visRange visMax 1/50(0.02) visRange visMax 5/300 visCategory 5 visRange visMax No light perception visCategory 9 visRange visMax Undetermined or unspecified |