Clinical studies have indicated that the disease progression of uveitis may be associated with multiple factors, including immune cell subsets, vitamin D levels, gut microbiota, and inflammatory cytokines levels. However, traditional clinical observational studies are susceptible to confounding factors when inferring causality, making it difficult to establish definitive causal relationships. Therefore, it is necessary to introduce alternative causal inference methods to validate the true associations between these potential factors and the onset and progression of the disease. Mendelian randomization (MR), as an emerging causal inference approach, has been widely applied in recent years to investigate the etiology of uveitis. By using genetic variants as instrumental variables, this method effectively overcomes the confounding bias and reverse causation issues inherent in traditional observational studies. In the context of uveitis research, MR analysis has also demonstrated significant value in mediation analysis, multivariable integration, and drug target prioritization.