Goji berries are a source of zeaxanthin, an antioxidant that may protect the eyes from high-energy light waves such as the sun's ultraviolet rays (along with the carotenoid lutein). Studies suggest that zeaxanthin and lutein in the eyes are associated with better vision and decreased likelihood of cataracts and age-related macular degeneration. Although goji berries are a source, zeaxanthin is found in many vegetables including kale, spinach and broccoli.