Vitamin E (tocopheryl acetate) has been studied for its potential role in supporting or treating cataracts due to its antioxidant properties. Cataracts involve oxidative damage to the proteins and lipids of the lens, and antioxidants like vitamin E theoretically could help slow this process by neutralizing free radicals. Epidemiological studies have shown mixed results: some observational studies suggest that higher dietary intake or blood levels of vitamin E are associated with a reduced risk of cataract formation. For example, the Nurses’ Health Study and some population-based studies have found a correlation between higher vitamin E intake and a lower incidence of cataracts.

However, randomized controlled trials (RCTs) and systematic reviews have generally failed to show a significant benefit of vitamin E supplementation in preventing or treating cataracts. The Age-Related Eye Disease Study (AREDS) found no significant reduction in cataract progression with vitamin E supplementation. Similarly, a 2012 Cochrane review concluded that there is insufficient evidence to support the use of vitamin E supplements for cataract prevention or treatment.

In summary, while there is a scientific rationale and some epidemiological support for the use of vitamin E in cataract prevention, high-quality clinical trial data do not validate its effectiveness. As a result, vitamin E is sometimes used based on its antioxidant properties, but strong scientific evidence for its therapeutic use in cataracts is lacking.