Factors affecting color vision: a systematic review

To summarize the influencing factors of color vision and their clinical implications, with an emphasis on the roles of genetic, environmental, demographic factors as well as ocular and systemic disorders.

Relevant literatures published from 2014 to 2024 were systematically retrieved from six databases including PubMed, Embase, Scopus, Web of Science, Cochrane Library, and Google Scholar. Search terms mainly covered color blindness, color vision deficiency (CVD), prevalence, incidence, protan, deutan, tritan, determinants, and risk factors. Eligible original English studies were screened according to predefined inclusion and exclusion criteria. Data extraction and quality evaluation were independently completed by two researchers. Qualitative systematic review was finally performed due to obvious inter-study heterogeneity.

A total of 50 eligible studies were enrolled. The prevalence of CVD was markedly higher in males than in females. Age, gender, ethnicity, and occupation were closely correlated with CVD. Males and individuals aged over 60y were more vulnerable to red-green CVD. Occupational ultraviolet radiation exposure, systemic diseases including diabetes mellitus and hypertension, as well as optic nerve lesions were confirmed as vital risk factors for abnormal color vision.

Apart from genetic and congenital factors, environmental exposure, aging, occupational characteristics, and various ocular and systemic diseases that impair retinal and optic nerve function can also affect color vision function. Clarifying these influencing factors helps ophthalmologists formulate targeted prevention schemes and individualized clinical interventions. Further well-designed longitudinal studies covering more diverse populations are still required in this field.