In a recent clinical trial, supplementation with high-dose antioxidants lowered the progression of lens opacities. These results differ from those of several other larger trials, in which no benefit to high-dose antioxidant supplementation was observed. Although a large body of observational evidence suggests that supplement use is associated with lower risk for cataract, there is insufficient evidence that high-dose antioxidants slow the progression of cataracts beyond that provided by multivitamins or healthful diets.