Visual Perception in Visual Snow Syndrome

Over the past decade, the neurological condition known as visual snow syndrome (VSS) has been increasingly acknowledged and studied, culminating in recognition within the International Classification of Diseases 11th Revision in 2025. Current diagnosis of VSS is entirely symptom based, with diagnostic criteria focusing on the perceptual experience of a suite of unusual visual phenomena. A burgeoning body of research on visual perception in VSS is contributing to the understanding of how such visual experience may arise within the visual system. Novel visual perceptual assessments are enabling quantification of interindividual differences in symptoms that may prove useful for future research, including clinical trials, and are shedding light on candidate mechanisms. This review aims to provide a current perspective on visual perceptual performance in VSS, with reference to likely neurobiology. In addition, we highlight exciting future directions and possible solutions to some of the challenges facing this nascent field of research.