Eye Colour, Ocular Straylight and Visual Stress: Exploring Potential Associations with Visual Discomfort and Cortical Processing

Visual stress is associated with visual discomfort, perceptual distortions and sensitivity to particular visual environments. Although research has investigated the optical characteristics of the eye and the role of visual cortical processing, the potential relationship between eye colour, ocular straylight and the lived experience of visual stress remains largely unexplored. This article proposes that these areas warrant investigation together. Existing research indicates that iris pigmentation may influence ocular straylight, while separate studies suggest that visual discomfort is associated with individual differences in visual processing. However, there is currently insuffi cient evidence to establish whether these findings are connected to visual stress. This exploratory review examines the rationale for investigating these potential associations, identifies important limitations in current knowledge and proposes a research agenda. It argues that interdisciplinary studies combining objective optical measurements with validated assessments of visual hypersensitivity and self-reported experience could help determine whether eye colour or straylight contributes to particular dimensions of visual discomfort. Rather than proposing a causal explanation, the article seeks to encourage empirical research into a potentially overlooked aspect of visual stress.