Superoxide Dismutase (SOD) is an antioxidant enzyme that catalyzes the dismutation of superoxide radicals into oxygen and hydrogen peroxide, thereby protecting cells from oxidative stress. The lens of the eye is particularly vulnerable to oxidative damage, which is a known risk factor in the development of cataracts. Several animal studies and some in vitro research have shown that increased SOD activity or supplementation can reduce oxidative damage in the lens and delay cataract formation. For example, animal models with enhanced SOD expression or treated with SOD-mimetic compounds often demonstrate a lower incidence or slower progression of cataracts compared to controls.

However, direct evidence from well-controlled human clinical trials is limited. Most human studies focus on the general antioxidant status in cataract patients, and few specifically evaluate SOD supplementation as a therapeutic intervention. Some commercial formulations include SOD as an ingredient for eye health, based on its antioxidant properties and the plausible mechanism of reducing oxidative stress in the lens. Despite this, the clinical efficacy of oral SOD supplements is questionable due to issues with bioavailability and degradation in the digestive tract.

In summary, while there is a scientific rationale and some preclinical evidence supporting the potential of SOD in cataract prevention or management, robust evidence from human clinical studies is lacking. The current evidence base warrants a moderate but not high rating.