For clinicians
A screening tool, not a diagnostic device.
For optometrists, neuro-optometrists, and functional-medicine clinicians who occasionally want a calibrated CSF curve from a patient between visits.
We don’t replace your standard exams.
VCS-Test is a free, calibrated, adaptive contrast sensitivity test that runs in a browser on a patient’s own phone, tablet, or laptop. The stimulus is Gabor patches at five spatial frequencies (1.5, 3, 6, 12, 18 cpd), the threshold procedure is a 2-down 1-up transformed up-down staircase, and the test produces a per-frequency log CS curve, AULCSF, and a normative band overlay. The methodology page has the full protocol.
It is not a substitute for the tests you actually run in clinic: refraction, slit-lamp, IOP, visual fields, OCT, fundus exam, dilation, Pelli-Robson chart on a calibrated wall, CSV-1000, or neuro-ophthalmic evaluation. A self-administered remote test on an uncontrolled display will always carry more noise than a clinically supervised measurement, even with our calibration steps. That’s a real limitation.
The frame we’d encourage is the one we use ourselves: a screening signal that a patient can bring to a visit, alongside their other complaints. Useful for the conversation, never the basis for a decision.
Four reasonable use cases.
Track changes over time
Repeat tests during recovery, remediation, or treatment let you watch the curve move rather than relying on a single in-clinic snapshot. The free tier saves results locally; the upcoming paid tier saves history server-side with a comparison view.
Sanity-check post-concussion vision
Letter-chart acuity often reads 20/20 after concussion while contrast sensitivity is degraded. This is a low-cost way for a patient to bring a CSF curve into a visit, especially between in-clinic neuro-optometric evaluations.
Look for the low-mid-band pattern
Reductions concentrated around 3–6 cpd — the peak of the CSF — are particularly informative across multiple conditions. A single isolated dip is usually noise; a coherent low-mid-band loss is worth attention.
Share results with the patient
The paid tier (coming soon) generates a shareable URL and a printable PDF so the patient can bring an actual curve to the visit, rather than a verbal complaint about night driving or screen reading.
A planned $99/month tier for clinics.
We’re building a provider tier with branded patient links, aggregate longitudinal views, and the ability to attach a result to a patient record without the patient paying anything. Pricing and exact features are not finalized; the consumer tier needs to validate first.
If you’d like to be told when it ships, register interest below — no commitment, no marketing list churn.
Register interest in the provider tier.
A short note is enough — your specialty, rough patient volume, and what you’d want from a provider tool.
Take it yourself before recommending it.
The test takes about three minutes after calibration. The methodology page has the technical detail.
Foundational papers.
- [1] Pelli D, Robson J, Wilkins A. The design of a new letter chart for measuring contrast sensitivity. Clinical Vision Sciences. 1988;2(3):187–199.
- [2] Mäntyjärvi M, Laitinen T. Normal values for the Pelli-Robson contrast sensitivity test. Journal of Cataract and Refractive Surgery. 2001;27(2):261–266.
- [3] Lesmes LA, Lu ZL, Baek J, Albright TD. Bayesian adaptive estimation of the contrast sensitivity function: the quick CSF method. Journal of Vision. 2010;10(3):17. PMC4439013.
- [4] Watson AB, Pelli DG. QUEST: a Bayesian adaptive psychometric method. Perception & Psychophysics. 1983;33(2):113–120.