And it’s dose dependent, meaning, the more animal food you eat, the greater your cataract risk:

Diet, Vegetarianism, And Cataract Risk, American Journal of Clinical Nutrition, May 2011

Objective: We investigated the association between diet and cataract risk in a population that has a wide range of diets and includes a high proportion of vegetarians.

Design: We used Cox proportional hazards regression to study cataract risk in relation to baseline dietary and lifestyle characteristics of 27,670 self-reported nondiabetic participants aged ≥40 y at recruitment in the Oxford (United Kingdom) arm of the European Prospective Investigation into Cancer and Nutrition (EPIC-Oxford) by using data from the Hospital Episode Statistics in England and Scottish Morbidity Records.

Results: There was a strong relation between cataract risk and diet group, with a progressive decrease in risk of cataract in high meat eaters to low meat eaters, fish eaters (participants who ate fish but not meat), vegetarians, and vegans. After multivariable adjustment, incidence rate ratios (95% CIs) for moderate meat eaters (50–99 g meat/d), low meat eaters (less than 50 g meat/d), fish eaters, vegetarians, and vegans compared with high-meat eaters (greater than 100 g meat/d) were 0.96 (0.84, 1.11), 0.85 (0.72, 0.99), 0.79 (0.65, 0.97), 0.70 (0.58, 0.84), and 0.60 (0.38, 0.96), respectively (P less than 0.001 for heterogeneity). Associations between cataract risk and intakes of selected nutrients and foods generally reflected the strong association with diet group.

Conclusion: Vegetarians were at lower risk of cataract than were meat eaters in this cohort of health-conscious British residents.

Compared with those who ate the most meat (≥100 g meat/d, that’s a little less than a quarter of a pound a day and up), the risks for developing cataracts were:

• Moderate meat eaters (50–99 g meat/d) decreased their risk by 4%
• Low meat eaters (less than 50 g meat/d) decreased their risk by 15%
• Fish eaters decreased their risk by 21%
• Vegetarians decreased their risk by 30%
• Vegans decreased their risk by 40%

Cataract is a clouding of the lens of the eye. This is what you see when you have it: