According to WHO. blindness is defined as a visual acuity of the better eye, less than -

Ans. is 'd' i.e., 3/60 Blindnesso WHO has proposed a uniform criterion and defined blindness as "Visual acuity of less than 3/60 or its equivalento In the absence of appropriate vision charts, the WHO has now added the "inability to count fingers in daylight at a distance of 3 metres" Xo indicates less than 3/60 or its equivalent.