Vitamin A deficiency blinds about half a million children each year, or 5 million per decade. Blindness affects people to an extent equivalent to about 5 life-years, for a total effect of 25 million life-years.

Human News aims to devote 1 character to each 40,000 life-years, or 1000 average lives. Thus, this story can have (25 million) / 40,000 = about 625 characters.