VisualSim is a free, browser-based visual symptom simulator. Patients with visual symptoms (visual snow syndrome, migraine aura, HPPD, floaters, scotomas, halos, color blindness and more) can overlay their experience onto a photo, video, or live camera feed, then share with their doctor exactly what they see — no need to describe it in words.

How do I show my doctor what my visual symptoms look like?

Open visualsim.org, choose a photo of your environment or turn on your phone's live camera, then adjust the sliders for the symptoms you experience (or pick a clinical preset like Visual Snow Syndrome or Migraine Aura). Hit 'Send to doctor' to share via link, email, SMS, or QR code. Your doctor opens the link and sees your exact slider configuration.

Is my photo or video data private?

Yes. VisualSim is 100% client-side — your photos, video, live camera frames, and slider settings never leave your device unless you explicitly click a share or save button. No account, no login, no server-side storage of user-generated content.

What visual conditions can I simulate?

32+ effects covering visual snow syndrome, migraine aura, hallucinogen persisting perception disorder (HPPD), posterior vitreous detachment, age-related macular degeneration, glaucoma, cataract, retinitis pigmentosa, Charles Bonnet syndrome, hemianopia and quadrantanopia (stroke), eye floaters, palinopsia (visual trails), color vision deficiency, oscillopsia, metamorphopsia, photopsia (flashes), starbursts, halos, photophobia, night blindness, tinnitus (audio), and more.

Is VisualSim a diagnostic tool?

No. VisualSim is a communication tool — it helps you show your doctor what you see. It is not a substitute for medical advice, examination, or treatment. If you are experiencing sudden flashes of light, new floaters, sudden vision loss, severe headache, or one-sided weakness, seek medical attention immediately.

Does VisualSim cost anything?

No. VisualSim is completely free, with no ads and no plans to ever change that. It was built by a patient with 15+ years of visual snow syndrome experience.

VisualSim — Visual symptom simulator

Show your doctor exactly what your vision looks like.

VisualSim is a free, browser-based tool for patients with visual symptoms. Overlay floaters, visual snow, migraine aura, HPPD, scotomas, halos, color blindness and more onto a photo or live camera feed, then share with your doctor via link, email, SMS, or QR code.

The interactive simulator requires JavaScript to run. To use it, please enable JavaScript and reload this page.

Conditions VisualSim helps communicate

Visual snow syndrome (VSS) — persistent TV-static across the visual field
Migraine aura — expanding scintillating C-arc with fortification spectrum
Hallucinogen persisting perception disorder (HPPD) — long-lasting visual disturbances after psychedelic use
Posterior vitreous detachment (PVD) — sudden Weiss ring floater + flashes
Age-related macular degeneration (AMD) — central blur with wavy lines
Glaucoma — gradual peripheral vision loss
Cataract — yellowed haze and halos at night
Retinitis pigmentosa (RP) — night blindness with peripheral loss
Charles Bonnet syndrome — recurring visual hallucinations in low-vision patients
Hemianopia — half-field visual loss after stroke
Eye floaters — drifting spots, strings, cobwebs in vision
Palinopsia — afterimages and motion trails
Color vision deficiency — red-green and blue-yellow color confusion
Oscillopsia — visual world bouncing or shaking
Metamorphopsia — straight lines appearing wavy

About

VisualSim is a free communication tool — not a diagnostic device. It was built by a patient with 15+ years of visual snow syndrome experience to help others describe their visual symptoms to doctors without needing to find the words.

All processing is done entirely on your own device. No images, video, or settings are sent to any server unless you explicitly share them. No account, no login, no tracking.

If you are experiencing sudden flashes of light, new floaters, sudden vision loss, severe headache, or one-sided weakness, seek medical attention immediately.