Yes, it is helpful for keeping eye health. Cranberry juice contains a large amount of vitamin C and vitamin A. As we all known, one cause of eye disorders is lacking of nutrients in diet. These nutrients include vitamin E, vitamin C, vitamin A and zinc. In other words, a daily vitamin that contains a beneficial formulation of nutrients that is rich in antioxidant nutrients. And cranberry juice can provide the nutrients to prevent some eye disorders. However, it could not provide the full amount of the recommended nutrients in a daily basis. It just has a positive impact on eyes and overall health. Therefore, it is not good to take too much cranberry juice, and may cause unexpected side effect.