We estimate the proportion of cataract surgery patients who have bilateral blindness or severe visual impairment at 10-47% (more). We estimate success in converting blindness or severe visual impairment to moderate visual impairment of 80%-95% (more). We estimate the cost of surgery at $50-$100 (more). Hence, we estimate the cost per blindness or severe visual impairment reversed at $112-$1,250.124

Givewell agrees with the $50 figure.