The four factors of visual hypersensitivity: definition and measurement across 16 clinical diagnoses and areas of neurodiversity

Subjective sensitivity to visual stimuli, including repeating patterns and bright lights, is known to associate with several clinical conditions (e.g., migraine, anxiety, autism), and also occurs in the general population. Anecdotal reports suggest that people might be sensitive to different types of visual stimuli (e.g., to motion vs lights). The visual Cardiff Hypersensitivity Scale-Visual (CHYPS-V) was developed to define and measure the different factors of visual hypersensitivity, using questions which focus upon functional impact rather than affective changes. Across five samples (n > 3000), we found four highly replicable factors using bifactor modelling. These were brightness (e.g., sunlight), repeating patterns (e.g., stripes), strobing (e.g., light flashes), and intense visual environments (e.g., supermarkets). The CHYPS-V and its subscales show very good reliability (α > .80, ω > .80) and improved correlations with measures of visual discomfort. We also used the CHYPS-V to delineate how these factors may differentiate clinical diagnoses and areas of neurodiversity from each other, and from the general population. Differences from individuals reporting no clinical diagnoses were most pronounced for the intense visual environments subscale, with individuals reporting a diagnosis of autism, fibromyalgia, or persistent postural perceptual dizziness (PPPD) scoring highest. Whilst many conditions showed a similar pattern of visual sensitivity across factors, some conditions (e.g., migraine, PPPD) show evidence of condition specific sensitivities (e.g., to pattern, or to strobing). Further to identifying the factor structure of visual hypersensitivity, CHYPS-V can be used to help investigate underlying mechanisms which give rise to these differences in visual experience.