Open Standard · v1.0 Draft · 2026

Open Visual Symptom
Standard (OVS)

A machine-readable JSON Schema standard for describing human visual and auditory perception disorders — condition-agnostic, implementation-neutral, and compatible with Open mHealth.

Schemas: CC BY 4.0 Code: MIT OVS 1.0 Draft
Read the Specification omH Converter Contact

What is OVS?

Visual Snow Syndrome, migraine aura, glaucoma, macular degeneration, and over a dozen other neurological and retinal conditions produce rich, subjective visual experiences. No machine-readable standard exists for describing them. Researchers rely on free-text descriptions that cannot be pooled across studies, compared across clinics, or fed into machine learning pipelines.

OVS fills this gap. Every symptom type extends a common base schema with severity (0–1), enabled, and an ISO 8601 effective_time_frame. Condition-specific fields are added in child schemas via JSON Schema allOf composition.

The primary reference implementation is the Visual Snow Simulator — an open clinical tool generating the first structured digital phenotype for VSS.

Schema Hierarchy

ovs:symptom-base
Root — all symptoms extend this
ovs:vss-snow
Visual Snow Syndrome
ovs:scotoma
AMD · glaucoma · migraine
ovs:hemianopia
Stroke · pituitary tumors
ovs:tunnel-vision
Glaucoma · retinitis pigmentosa
ovs:glare
Cataract · VSS
ovs:halo
Cataract · corneal
ovs:contrast-loss
Cataract · AMD · VSS
ovs:palinopsia
VSS · neurological
ovs:photopsia
VSS · PVD · migraine
ovs:charles-bonnet
Visual impairment
ovs:migraine-aura
Migraine with aura
ovs:diplopia
Binocular disorders
ovs:metamorphopsia
AMD · epiretinal membrane
ovs:oscillopsia
Vestibular · nystagmus · VSS
ovs:floaters
PVD · myopia · VSS
ovs:blue-field-entoptic
VSS (almost universal)
ovs:cvd
Congenital and acquired CVD
ovs:tinnitus
VSS comorbidity ~80%
ovs-profile:vss
VSS condition profile
OVS Session Document
Root session wrapper

Minimal Session Document

Every symptom requires ovs_type, ovs_version, enabled, severity (0–1), and effective_time_frame (ISO 8601 UTC). Additional fields are symptom-specific.

{
  "ovs_version": "1.0",
  "session_id": "550e8400-e29b-41d4-a716-446655440000",
  "recorded_at": "2026-05-31T12:00:00Z",
  "profile": "ovs-profile:vss",
  "subject_id": "VS-3A7F21",
  "symptoms": [
    {
      "ovs_type": "ovs:vss-snow",
      "ovs_version": "1.0",
      "enabled": true,
      "severity": 0.72,
      "grain_size": 0.4,
      "speed": 0.3,
      "alpha": 0.6,
      "pattern": "random",
      "color_mode": "white",
      "effective_time_frame": { "date_time": "2026-05-31T12:00:00Z" }
    },
    {
      "ovs_type": "ovs:tinnitus",
      "ovs_version": "1.0",
      "enabled": true,
      "severity": 0.45,
      "subtype": "pure_tone",
      "base_frequency": 4000,
      "volume": 0.3,
      "effective_time_frame": { "date_time": "2026-05-31T12:00:00Z" }
    }
  ],
  "wellbeing": {
    "anxiety": { "value": 6, "scale": 10 },
    "sleep_hours": 6.5
  }
}

Open mHealth Bridge

OVS maps onto Open mHealth data points using schema_id.namespace = "ovs". The converter tool accepts a Visual Snow Simulator export (ZIP or JSON, v4–v6) and downloads an omH-compatible JSON file.

Open the omH Converter →

VSS Simulator Export Reference

The Visual Snow Simulator export format (v6) is an OVS-compliant implementation. Its field mapping is documented as a reference for other implementors.

JSON Schema (v6) · Field documentation

Authors & Affiliation

Péter Szigeti — Research Lead, Entropy Vector Group S.R.L.
Joint PhD candidate, Óbudai University / Sapientia Hungarian University of Transylvania

Dr. László Bakó, Ph.D. — Group Research Leader, Sapientia Hungarian University of Transylvania

Supported by the Domus Group Research Grant (Sapientia Hungarian University of Transylvania). NLnet NGI0 Commons funding application in progress.