Photophobia and Poor Night Vision are the Most Disruptive Symptoms of Visual Snow Syndrome

Visual Snow Syndrome (VSS) is a visual condition characterized by the continuous presence of specks/dots (visual snow) over one’s field of vision, in addition to two or more visual disturbances including afterimages, trails behind moving objects, blue field entoptic phenomena, photophobia, and poor night vision. VSS may impact reading and driving, but the extent to which different symptoms disrupt daily functioning remains unknown. Here, we examined the impact of VSS symptoms on everyday life by surveying individuals with VSS (n=29). For each symptom, participants rated its frequency, duration, and the degree to which it bothered them. Bothersomeness was rated on a four-item scale, “is not bothersome”, “is annoying but manageable”, “is bothersome”, and “severely affects my ability to do daily tasks.” Blue field entoptic phenomena were the most common symptom (78%) followed by poor night vision (71%), photophobia leading to headaches (71%), and afterimages (64%). Trails behind moving objects were the least common symptom (43%). 71% of participants rated visual snow as “annoying but manageable”. However, the most impactful symptom was photophobia leading to headaches; a majority reported that it was either bothersome (30%) or severely affected daily tasks (35%), with no one reporting it “is not bothersome”. Poor night vision was also frequently rated as bothersome (55%) or severely affecting daily tasks (15%). Some participants with floaters and trails responded that they severely affect their ability to do daily tasks (27% and 25% respectively), while others said these symptoms are not bothersome (40% and 50% respectively). Preliminary results suggest correlations between self-report measures of afterimages and trails with the salience (i.e., RMS contrast) of visual snow (quantified by a behavioral matching task). Together, our results indicate that photophobia, poor night vision, and other symptoms associated with VSS may be more disruptive than visual snow itself.