Eye Tracking Applications in Colour Vision Assessment

Abstract Traditionally, colour vision assessment relies on the patient’s subjective response. The current study introduces an objective approach using eye movement analysis to explore the perception of moving chromatic stimuli. Chromatic sensitivity was assessed using Dynamic-Static Colour Vision Test (DSCVT) stimuli. A total of 20 (15 female and 5 male) participants (aged 18–28 years, 21.7 ± 2.2) were recruited for the study. During stimulus presentation, participants were instructed to focus on the chromatic stimuli and provide a subjective response at the end of the demonstration. Simultaneously, eye gaze coordinates were recorded to assess chromatic sensitivity objectively. Sensory thresholds were determined using the method of constant stimuli, with detection probabilities computed through psychometric function fitting. Smooth pursuit eye movements were analysed using algorithms developed by Larsson et al. [1] and Nyström et al. [2], enabling the objective identification of the direction in which tracking distance was the longest. Higher chromatic saturation increased smooth pursuit detection; however, inconsistencies in individual performance prevented consistent modelling of the psychometric function due to response variability. In cases where stimulus intensity exceeded threshold levels, correct responses were often given without tracking the object, limiting smooth pursuit-based assessment. Smooth pursuit movements alone were insufficient for severity classification of colour vision deficiencies; further research is needed using additional eye movement metrics.