This data set comprises eyetracking data of human visual search patterns when assessing equine facial expressions indicative of various pain levels. Hundred and eight individuals (N=108), classified into three groups (affinity with horses (N=60), pet owners with no affinity with horses (N=32), and individuals with no affinity with animals (N=16) evaluated four photos of horses with different levels of pain, while having their eye moments recorded using eye tracking glasses. Error score, calculated by comparing participant scores to Gold Standard Visual Analogue Score levels and fixation metrics (number of fixations and duration of fixations) were analysed across four Areas of Interest (AOIs) of the horse's face, namely eyes, ears, nostrils, and mouth.