Like his older brothers, 12-year-old Louis Corbett is going blind. They have a genetic disease called retinitis pigmentosa, which deteriorates vision over time. But Corbett, who hails from New Zealand, isn’t giving up. He loves to watch sports more than anything, so his parents thought a world tour — to see sports and some breathtaking locations around the world, before his sight is permanently lost — would be a dream come true. Corbett’s tour story went viral online, and the next thing you know Warren Casey, CEO of Boston-based Ceiba Solutions, was cosponsoring the tour and making sure it included a stop in the city to see a Celtics game, given that young Louis is a major C’s fan. While in town for the game, Corbett and his family stopped by Massachusetts Eye and Ear’s Ocular Genomics Institute to learn about the latest in eye research from Luk Vandenberghe.