How Spect-IT Works
Vision screening in four steps
From calibration to results — here's how Spect-IT delivers accurate, repeatable vision screening.
Calibrate your screen
Use a credit card to calibrate screen size (pixels/mm) and set your viewing distance. This ensures optotypes appear at the correct physical size for screening accuracy.
Follow the guided journey
Our guided journey recommends test order and walks you through pre-test setup: distance, lighting, glasses on/off, occlusion. Progress is saved — resume anytime.
Complete screening tests
Eight eye screening tests: Visual acuity (Sloan ETDRS), contrast sensitivity (logCS), color vision (confusion-line plates), astigmatism (radial patterns), visual field (Amsler grid), stereoacuity (random-dot stereograms), pupillary distance (PD), and refractive screening (pinhole test). Plus hearing screening with pure-tone audiometry.
Get your summary & PDF
Receive a screening results summary with logMAR scores, per-eye breakdown, and recommendations. Export as PDF to bring to your optometrist appointment.
Screening Methodology
Visual Acuity
Standard Sloan optotypes (C, D, H, K, N, O, R, S, V, Z) at WHO-compliant visual angles. 6/6 (20/20) = 5 arc minutes per stroke. ETDRS methodology with 5 letters per line. LogMAR scoring for clinical reporting.
Color Vision
Confusion-line pseudoisochromatic plates (NOT Ishihara) for protan and deutan deficiencies. Control plates mark unreliable tests as inconclusive. Procedurally generated dot fields (~2000 dots) ensure copyright-free testing.
Contrast Sensitivity
Pelli-Robson-inspired low-contrast optotypes assess vision in reduced lighting. Screens for cataracts, glaucoma, macular degeneration. LogCS scoring.
Astigmatism
Radial fan, cross-grid, and clock dial tests identify corneal irregularity and orientation. Results inform cylinder/axis estimates.
Visual Field (Amsler Grid)
Central 10° macular screening for metamorphopsia, scotomas, and distortion. Per-eye testing with fixation monitoring. Critical early indicator for macular conditions.
Refractive Screening
Compares uncorrected acuity to pinhole acuity to detect refractive blur — tells you if correction may help, NOT a prescription. Does NOT generate sphere, cylinder, or axis values. Results are NOT dispensable. Consult an optometrist for prescriptions and eyewear.
Stereoacuity
Random-dot stereogram test screens binocular depth perception using red-cyan anaglyph display. Measures stereo threshold in arcseconds. Requires anaglyph glasses.
Pupillary Distance
Manual marker-based PD measurement with calibrated screen. Provides screening estimate of distance between pupil centers. NOT for ordering glasses — professional measurement required.
Screening Note: Spect-IT uses screen-based testing with calibrated physical sizing and research-based protocols. Validation study is in progress with optometrists. All results are screening estimates for informational use — not medical diagnoses, clinical assessments, or dispensable prescriptions. For professional eye care and eyewear prescriptions, consult a licensed optometrist or ophthalmologist.
Ready to test your vision?
Start Your Screening →Technical Architecture
Distance Measurement
Uses depth sensors on supported devices for distance measurement. Falls back to camera-based depth estimation on all other devices.
Computer Vision
Face landmark detection, pupil geometry extraction, and eye tracking for accurate test positioning.
Screening Engine
Algorithms analyze test results to provide screening-level estimates with confidence scores and quality flags.
Privacy-First
Camera used only during tests for positioning. Test results are stored securely with your consent. We never sell your data.