Investigational · for personal tracking and research

See what your eyes can detect.

Explore visual contrast sensitivity with a smartphone-based test designed for personal tracking and research.

Start visual contrast testExplore the science →

About 3 minutes per eye · no account · results stay on your phone

A circular patch of soft grey bars leaning slightly to the left, fading out at the edges.
Figure 1 A Gaussian-windowed sine grating leaning 15° left, the kind of pattern the test shows. Illustration, not a test stimulus.

How the test works

  1. 1Hold the phone at reading distanceThe front camera measures eye-to-screen distance from the size of your iris. Images never leave the phone.
  2. 2Cover one eye, answer the tiltEach faint patch leans left, stands upright or leans right. Tap the matching button. 45 patches per eye.
  3. 3Read your result, keep the recordOne headline says what to do next. Every patch shown and every answer given is kept with the conditions.
Three patches of grey bars: leaning left, upright, and leaning right.
Figure 2 The three possible answers: left, upright, right. Illustration, not a test stimulus.

What contrast sensitivity measures

How faint a pattern each eye can still see, at five bar widths from coarse (1.5 cycles per degree) to fine (18). It depends on the clarity of the eye and on processing in the retina, optic nerve and brain, and often changes before a standard letter chart does.

Five patches of grey bars, from wide bars on the left to very fine bars on the right.
Figure 3 The five bar widths, columns A to E, in cycles per degree at the test distance, drawn here at reduced scale. Illustration, not a test stimulus.

Why track it

Visual function and ageing. Contrast sensitivity declines with age, cataract and other eye conditions, and is linked to falls and night-time driving.

Environmental health and the exposome. Group studies have reported lower contrast sensitivity in occupants of water-damaged buildings and after some neurotoxic exposures. These are group findings; they do not allow any one person's result to be traced to an exposure.

Your own baseline. Two runs set it; repeat every few months under the same conditions and see whether anything changes.

Understanding your result

Nothing in this result calls for actionKeep it as a baseline; repeat in about three months.
Repeat to confirmConditions or answers were uncertain. Repeat within a week.
Worth an eye checkSee an optometrist and take the report with you.

The headline says what to do next, never what the cause is. Rules guidance-v1-provisional, set before any normative data and open to revision.

Validation status

Software verification: see the test page.
Physical measurement: not yet performed.
Clinical validation: not yet performed.

About the scientific lead

Dr Cameron Jones, PhD, environmental microbiologist and co-author of the Australian Mould Guideline 2026. Biological Health Services · drcameronjones.com

Privacy

No account, no tracking. The camera is processed on the phone and never stored. Results stay on your device unless you share them. Privacy notice

Start visual contrast testMethod explainer (PDF)