To prevent the slow degradation of the eyes, it is essential to consume certain nutritional and dietary supplements for eye health. Ten of the best supplements for eye health are: Vitamin A: Vitamin A is required in large doses to ensure proper functioning of the retina, especially at night. Deficiency of vitamin A may cause ocular disorders like Xeropthalmia or night blindness. Vitamin A also plays a vital role in preventing dryness in the eyes.