Definitions of blindness: WHO definition of blindness: "Visual acuity of less than 3/60 (Snellen) or its equivalent". Economical blindness: Vision in better eye <6/60 to 3/60 Social blindness: Vision in better eye <3/60 to 1/60 Legal blindness: Vision in better eye <1/60 to perception of light Absolute/total blindness: No light perception Ref: Ophthalmology By A. K. Khurana, 3rd edition, Page 443, 444.