Authors: Wiktoria Stańska, Anna M. Torbus, Przemysław Rusztyn, Piotr Maciejewicz
Visual Snow Syndrome (VSS) is a neurological condition in which individuals see continuous flickering dots across their entire visual field, often described as resembling television static or falling snow. These visual disturbances can appear both with open and closed eyes and may become more noticeable in dark environments or against plain backgrounds. Despite its impact on daily life, the condition remains difficult to diagnose because standard ophthalmological and neurological tests are often normal.
This case report describes identical twin sisters, both 24 years old, who experience VSS and were admitted to the Ophthalmological Department of Infant Jezus Clinical Hospital in Warsaw. Since childhood, both sisters have perceived bright, flickering dots across their visual field, even when their eyes are closed. Although they share the same condition, their symptom experiences differ slightly.
One sister reported severe light sensitivity, difficulty seeing at night, visual motion disturbances, flashes of light, afterimages, and tinnitus. The other experienced afterimages, floaters, blind spots in her vision, and occasional tinnitus. In both cases, the symptoms intensified during fatigue, stress, or lack of sleep. However, extensive medical testing, including detailed eye examinations, brain MRI scans, blood tests, and cerebrospinal fluid analyses, showed no significant abnormalities except for mild nearsightedness.
Interestingly, both twins were also diagnosed with conditions such as fibromyalgia and tinnitus, which supports theories that visual snow syndrome may be connected to broader sensory processing differences within the nervous system. The complexity of VSS lies in the fact that there is currently no objective test that confirms the diagnosis, meaning clinicians rely primarily on patients’ descriptions of their visual experiences.
What makes this case particularly notable is that reports of identical twins experiencing VSS have not previously been documented. The presence of the condition in both sisters suggests that genetic factors may play a role in the development of VSS. Overall, this report highlights the complexity of the condition and emphasizes the need for greater awareness, clearer diagnostic pathways, and continued research to better understand and support individuals living with visual snow syndrome.