In sub-Saharan Africa, up to 30% of kids under age 5 are at risk of going blind—among other conditions—for one simple reason: they don’t get enough eye-nurturing vitamin A. But what if the bananas that make up a lot of their diet could be re-engineered to deliver it? That’s the idea that struck Australian biogeneticist James Dale when he visited Uganda in the early 2000s. With backing from the Bill & Melinda Gates Foundation, Dale and his team began developing a vitamin-A-enriched “superbanana”; human trials start soon in the U.S. In Africa, they will be introduced using what Dale calls a “reverse Ponzi scheme” to spark adoption. Village leaders will be given 10 free superbanana plants to grow, on the condition that they give at least 20 new shoots to other villagers, who will do the same. “These bananas could potentially solve” a major health problem, Dale says.