Acai berry has a lot of antioxidants. Pilots used to eat bilberry to improve their vision, which also has antioxidants. Most fruits and vegetables with dark pigment (goji berry, blueberries, kale) are touted as “superfoods” as they have a high concentration of antioxidants which help scavenge free radicals in the body (reduce risk of cancer). They also help promote healthy ocular metabolism and reduce the risk of macular degeneration (leading cause of blindness in people over 55 in the US).