Binocular Vision Dysfunction, Visual Snow Syndrome, & Long COVID
As a likely result of my hypermobile Ehlers-Danlos Syndrome I recently was diagnosed with Binocular Vision Dysfunction, treatment of which included 6 months of post-traumatic brain injury vision rehabilitation training despite no traumatic brain injury. This therapy greatly improved my convergence and basically all visual categories and also reduced frequency of my headaches, neck pain, motion sickness etc. My neuro-optometrist noted my posture and neck compression was likely driving some of my visual disturbances, related to my connective tissue laxity. (I’ve had BVD & VSS since childhood which COVID then worsened)
I was also diagnosed with Visual Snow Syndrome, ie my field of vision is made up of static, lights, shapes, and flashes, which I’ve had since as early as I can remember and has been connected to things I also have like migraine and neurodivergence and is likely due to hyperexcitability of neurons in the brain’s visual cortex.
As a kid I thought I was just seeing the atoms making up physical matter in space, turns out that’s impossible lol. I experience this increased sensory gain in all my systems it seems, and these overlapping patterns are being connected in new ways including to Long COVID.
It’s been really interesting to learn how these ocular manifestations intersect with Long COVID. A case series from the Visual Snow Initiative (Peculiar Visual Symptoms Following COVID-19 Illness: COVID-19 And Visual Snow) reported five patients who developed classic VSS symptoms, constant static, palinopsia, light sensitivity, and dizziness in bright light, following mild COVID-19 infection, in some cases appearing up to two years after recovery.
Most had no prior neurological history and normal ophthalmic exams, which points toward COVID-19 acting as a precipitating trigger for VSS in people who may have had an underlying susceptibility, rather than causing direct structural damage.
Another study from the Visual Snow Initiative (Long COVID And Visual Dysfunction: Exploring Visual Snow Symptoms And Neuro-Optometric Findings) looked at this overlap, though it’s worth noting it reviewed records of 47 patients already presenting to a Neuro-Optometric Rehabilitation Clinic who had been infected with COVID, so it captures a help-seeking symptomatic clinical population rather than Long COVID broadly.
That said, the patterns that emerge are striking. They found many overlapping symptoms with LC patients. 77% of patients had vestibular-related issues. Also common were brain fog and fatigue (51%), Light sensitivity (66%), Headaches (66%), Eyestrain (66%). 92% of patients had BVD.
Notably, 40% also self-reported a prior concussion history, which is a real confounder, which is a common previous issue I hear from many in these communities.
What I find most interesting is the authors’ observation that these patients look clinically similar to post-traumatic vision disorder patients, the same profile seen after TBI. That suggests Long COVID related visual manifestations may also be related to and or producing a neurological insult that disrupts visual and vestibular function in the same way a brain injury does, which is part of why neuro-optometric rehabilitation, the exact therapy that helped me despite having no TBI, is potentially a meaningful intervention for LC patients too.
Visual snow symptoms were also noted in this patient group, which is significant given how under-studied VSS remains, and adds to the emerging picture of cortical hyperexcitability as a thread running through Long COVID, hEDS, Neurodivergence, and conditions like VSS.
Studies:
Study: Peculiar Visual Symptoms Following COVID-19 Illness: COVID-19 And Visual Snow
Study: Long COVID And Visual Dysfunction: Exploring Visual Snow Symptoms And Neuro-Optometric Findings
🔗: https://www.visualsnowinitiative.org/research/long-covid-and-visual-signs-and-symptoms/
