This systematic review from 2020 outlined mechanisms of action and related evidence of beta carotene’s benefits to ocular health. Outlining the role in preventing oxidative damage to various eye structures and prevention of diseases such as age-related macular degeneration, cataracts and diabetic retinopathy. The review includes 26 clinical trials whereby carotenoids were assessed for ocular health.
Johra, F. T., Bepari, A. K., Bristy, A. T., & Reza, H. M. (2020). A Mechanistic Review of β-Carotene, Lutein, and Zeaxanthin in Eye Health and Disease. Antioxidants (Basel, Switzerland), 9(11), 1046. https://doi.org/10.3390/antiox9111046