A machine-readable JSON Schema standard for describing human visual and auditory perception disorders — condition-agnostic, implementation-neutral, and compatible with Open mHealth.
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.
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
}
}
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.
An experimental HL7 FHIR R4 Bundle export (Patient + Observation resources) is also available. Symptom codes currently use a provisional openvisual.org CodeSystem until a LOINC/SNOMED CT terminology binding is agreed.
The Visual Snow Simulator export format (v6) is an OVS-compliant implementation. Its field mapping is documented as a reference for other implementors.
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 Hungarica group homeland research scholarship of the Hungarian Academy of Sciences, in collaboration with Dr. László Bakó (Sapientia Hungarian University of Transylvania). NLnet NGI0 Commons funding application in progress.