Can Long COVID Affect Your Vision? Signs of Binocular Vision Dysfunction
Yes. Long COVID can cause vision problems like light sensitivity, blurry vision that comes and goes, dizziness, double vision, and trouble reading. One common cause is binocular vision dysfunction (BVD), where inflammation in the brain disrupts how your two eyes work together. The good news: it can often be rehabilitated with vision therapy.
Wearing sunglasses inside? Dizzy in the grocery store? Words jumbling on the page? Hear this:
You might not still be sick. You might just still be symptomatic.
There's a difference. And it changes everything about how you heal.
Key takeaways
- Long COVID, Epstein-Barr, and CIRS can affect the brain like a concussion, and that shows up in your eyes.
- Binocular vision dysfunction (BVD) means your brain can't use your two eyes together properly.
- Common symptoms: light sensitivity, dizziness, blurry or double vision, headaches, trouble reading, anxiety in busy places.
- A simple finger test at home can flag possible BVD.
- Vision therapy helps 80 to 90% of patients improve, according to neuro-optometrist Dr. Trevor Smith.
My story: long COVID took my vision
In 2021, months after burying my husband, I got COVID. It turned into long COVID, reactivated Epstein-Barr, and led to CIRS. Tremors, tinnitus, derealization. And my vision started going.
I'm about 95% better now. But a recent flare tanked my vision again. Light was unbearable. One eye was blurry, the other perfect. Driving felt like dissociating.
So I called Dr. Trevor Smith, a neuro-optometrist at NUsight Vision Therapy Clinic in Provo, Utah. He speaks the language of infections, CIRS, and Epstein-Barr. So I put a microphone in front of him. ๐
๐ง Listen to the full podcast episode with Dr. Trevor Smith
What is binocular vision dysfunction (BVD)?
Binocular vision dysfunction (BVD) is when your brain no longer knows how to use your two eyes together. Your eyes have to be perfectly aligned, perfectly focused, and able to move accurately from one spot to the next. When one of those skills is damaged, by injury, infection, or inflammation, you get symptoms all over your body.
What are the symptoms of binocular vision dysfunction?
- Eyes not pointing together: poor depth perception, trouble driving, missing your food with your fork (yes, really)
- Eyes not focusing: headaches, light sensitivity, blurry vision that comes and goes
- Eyes not tracking: "I used to read a book a week. Now the words jumble."
- Brain stuck in fight or flight: anxiety, derealization, overwhelm in busy places, snapping at your kids out of nowhere
That last group is the one nobody connects to vision. But if your brain can't tell where things are, it doesn't feel safe. And an unsafe brain stays in fight or flight.
Why does long COVID cause vision problems?
Dr. Smith's concussion patients and his long COVID patients look almost exactly the same. Same symptoms, same treatment. So he treats long COVID, CIRS, and Epstein-Barr as an acquired brain injury.
- About 80% of your brain is involved in vision. Brain inflammation shows up in your eyes.
- Lost your taste or smell with COVID? That signals brain inflammation. In his experience, 80 to 90% of those patients also have vision symptoms.
So many of you keep scrubbing your house for mold, thinking you're still exposed. Check your brain. It might be damage, not exposure. And damage can be rehabbed.
Want to go deeper on this? Listen to Long COVID and the Brain: Can Neurological Damage Be Reversed?
Why is light sensitivity so bad after COVID?
About 94% of your vision is peripheral. Normally your brain filters out the irrelevant stuff: the lights, the shelves, the people, the music.
Inflammation pushes you into fight or flight and that filter shuts off. Now your brain scans everything. What's that? Is that coming at me? It can't keep up, so it shuts you down with a headache, dizziness, nausea, or blur.
Dr. Smith's analogy: healthy is I-15 at midnight. Inflamed is every exit closed and a semi rolled across three lanes.
Fight or flight also dilates your pupils, so more light pours in with no filter. That's why light sensitivity is usually the last symptom to go.
How do you know if you have BVD? Try this 10-second test
- Hold a finger or pen out in front of you at arm's length.
- Slowly bring it toward your nose.
- It should stay one finger almost all the way in. Blurry up close is normal.
- If it goes double, your eyes are struggling to point together. That's a sign of BVD worth getting checked by a neuro-optometrist.
This is not a diagnosis. It's a flag.
Your eyes are one clue. What else is your body telling you? Inflamed brains don't break down on their own. Something underneath went first. ๐ Take the free Root Causes Quiz and find out where your body broke down.
How is binocular vision dysfunction tested?
After a regular eye exam, a neuro-optometrist tests how your brain uses your eyes:
- Near-point test: the finger test (Dr. Smith uses a little fish ๐)
- Prism strain test: how your brain handles eye stress. Mine was dramatic. "No, please don't."
- Depth perception test: are you at 30%, 50%, or 90%?
- Eye movement (DEM) test: reading numbers. The NFL once used it for concussions, until players sandbagged it. ๐
- Color field mapping: when your brain actually processes color in your side vision. This map picks your "magic glasses."
What is vision therapy for long COVID?
Vision therapy retrains your brain to use your eyes together again. Dr. Smith says it's less like physical therapy (strengthening a muscle) and more like re-teaching your brain to ride a bike. The muscles work. The brain lost the skill.
Optometric phototherapy (the "magic glasses")
Stupid simple. Colored lenses, 20 minutes a day, looking at the sky (not the sun). For the first time since childhood, I felt zero background anxiety.
- More is not better. I did it twice on day one and was out cold, hungover-tired. Spicy nervous systems: go gentle.
- I wasn't perfect. I did only 10 to 12 sessions and my color maps still improved drastically. See the before and after in my BVD highlight on Instagram.
My dizziness is gone. I can't remember the last time I was dizzy.
Can vision problems from long COVID be fixed?
80 to 90% of Dr. Smith's patients improve. Not 100% resolved. The goal is at least 80% of a normal life, with weaker, shorter flares.
Vision is one piece of a team sport. I'm doing glasses, brain rehab, and diet to bring inflammation down from every angle.
His best analogy: it's piano lessons. The recital is your next flare. Practice now, fewer mistakes then.
Five years ago my brain felt like it was melting. Today parts of me I lost ten years ago are coming back. Please don't lose hope.
Frequently asked questions
Can long COVID cause light sensitivity?
Yes. Brain inflammation can keep your nervous system in fight or flight, which dilates your pupils and turns off your brain's visual filter. More light gets in and your brain can't sort it, so normal lighting feels overwhelming.
Can long COVID cause blurry vision in one eye?
It can. Blurry vision that comes and goes, or one eye that seems weaker than the other, can be a sign that your brain isn't coordinating your eyes, which is called binocular vision dysfunction. Glasses usually can't fix this kind of blur.
Who treats binocular vision dysfunction?
A neuro-optometrist, also called a developmental or behavioral optometrist. They focus on how your brain uses your eyes, not just how clearly you see.
How long does vision therapy take to work?
It's different for everyone. Dr. Smith described patients who arrive wearing sunglasses and a hat and don't need them three months later. Light sensitivity is usually the last symptom to improve.
Where do you start?
Vision is just one piece of the puzzle. If your brain is inflamed, something underneath it broke down first.
That's exactly what the Order of Healing™ maps out: 8 steps, from mindset and mitochondria all the way up to brain health. Because you're not broken. You're out of order.
๐ Download the free Order of Healing™ Guide and find out what to support first.
๐ง Listen to the full episode on the Gutsy Health Podcast.
Want to see Dr. Smith? Find NUsight Vision Therapy Clinic at newsightvt.com in Provo, Utah.
Related: Can Long COVID Brain Damage Be Reversed? with Dr. Oliver.
This post is for education only and isn't medical advice. Talk with a qualified provider before starting any new therapy.
