Decisions about sight are only as reliable as the measurement behind them.
Visicomp Research develops tests and instruments for the measurement of visual function — for use in research studies, in visually demanding occupations, and in the clinic.
From research studies to routine use.
Visicomp Research began in academic vision research and now supplies software and instrumentation for a broader range of settings — commercially in visually demanding occupations, and clinically in eyecare. In most cases the work begins with a question someone needs answered — whether a regulator, a clinician or a research group — and ends with the means to answer it.
Vision assessment comes down to a decision: fit or unfit for a role, refer or reassure, treat or monitor. But every decision needs a defensible basis — especially where careers and safety depend on the outcome. Our tests measure the limit at which a visual signal can still be detected, with repeatability such that a change in the result reflects a change in vision, not in the test.
How much sensitivity a task demands, and what an error would cost, cannot be answered from the eye alone. Measurement across occupational and clinical groups, and modelling of how performance relates to task demands, is what ensures that a requirement is founded on evidence rather than convention.
How we build a test.
Every test we build goes through the same three stages, in the same order.
One signal at a time
Stimuli are designed so that only one visual signal — colour, luminance or flicker, for example — can be used to detect them. Other cues are masked or removed, so a correct response cannot be explained by anything else.
Finding the threshold
The threshold is the faintest level at which the signal can still be detected. Finding it accurately, and finding it quickly enough to be practical, is what the measurement procedure is designed to do.
Against the normal range for age
A threshold on its own says little. Interpreted against normative data for the observer's age, it separates ordinary ageing from early loss, and locates an individual's performance against a known standard.
The same stimulus every time
Chromaticity is calibrated to within 0.001 in CIE 1931 xy and kept there — this stable and reproduceable calibration ensures reduced variability between sessions and instruments.
A selection of past work.
Instruments, tests and research
- Colour Assessment and Diagnosis (CAD) test, developed with research funding from the UK Civil Aviation Authority and Transport for London. Adopted by aviation and maritime authorities as the basis for occupational colour vision standards, and in use internationally. Supplied by COL-Aeglia Ltd
- Advanced Vision and Optometric Tests (AVOT), a suite covering acuity and contrast sensitivity, rod- and cone-mediated flicker sensitivity, and intraocular light scatter. Supplied by COL-Aeglia Ltd
- P_SCAN system for binocular and dichoptic pupillometry with simultaneous eye tracking, first described in 1991, for research into retinal and post-retinal visual pathways. Research instrumentation
- Modelling of visual processes and the mechanisms underlying visual performance, developed alongside the experimental work and published in the peer-reviewed literature. Research programme
- Assessment of vision changes in gene therapy trials. Applied Genetic Technologies Corporation
Occupational vision standards
- Definition of colour vision requirements for train drivers, and introduction of a safer and less variable colour assessment protocol. UK mainline rail
- Review of colour vision assessment for maritime navigational lookout duties, and new assessment protocols. UK Maritime & Coastguard Agency
- Analysis of colour assessment outcomes, and a system for accurate classification of colour vision loss with relevance to ARTD requirements. British Army
- Validation of Low Emission Zone signage for observers with congenital colour deficiency. Transport for London
- Assessment of the visual effects of tinted lenses for train operators. Transport for London
- Analysis of colour vision assessment practice with relevance to the electrical industries. Joint Industry Board
- Study of hypoxic effects in relation to time-dependent visual adaptation. QinetiQ
- Delivery of training courses on colour assessment, visual performance and minimum vision requirements in visually demanding occupations. Regulatory & occupational health providers
- Photometric analysis of major crime scenes, establishing what could and could not have been seen under the lighting conditions at the time. Hampshire Constabulary
Work carried out by Visicomp Research and, in many cases, in collaboration with the Centre for Applied Vision Research at City St George's, University of London.
What we are building now.
Display calibration
A novel, accurate photometer for calibration of visual displays. A calibration system that minimises crosstalk and primary instability in visual displays. The more accurate the display, the smaller the difference a test can resolve in a given number of trials.
Colour vision screener
A compact colour vision screener, designed and validated to close to 100% sensitivity and specificity when screening for red/green and yellow/blue deficiencies.
Instruments for early detection of eye disease
Instrumentation and tests based on new research findings, targeting specific diseases of the eye — including measures of rod and cone mediated flicker sensitivity and pupil response — designed for ease of clinical use
Clinical studies
Investigation of patients whose visual difficulties are not explained by standard examination — often where the need for a new measurement first becomes apparent.
Professor John Barbur
Scientific LeadProfessor of Optics and Visual Science at City St George's, University of London, and founder of its Centre for Applied Vision Research. His work on colour vision and its measurement underlies the CAD test and much of the assessment practice now used in aviation and other visually demanding occupations.
He has published over 250 papers, and continues to work on the design of tests and on the visual mechanisms they depend upon.
Dr Gary Bargary
Technical LeadInstrument design, software, display calibration and validation — including the low-level graphics work that preserves ten-bit colour and frame-accurate timing on compact, low-cost hardware. He holds a PhD in vision science and carried out post-doctoral research with Professor John Mollon in Cambridge and with Professor Barbur in London.
- Acta-EVER Honorary Lecture and silver medal, in recognition of achievements in eye and vision research. European Association for Vision and Eye Research · 2024
- Newton Medal, for contributions to fundamental research and practical applications in colour vision. Colour Group of Great Britain · 2024
- Callendar Award, for outstanding contribution to the art of instrumentation for vision research. Institute of Measurement and Control · 2023
- Albrecht-Ludwig-Berblinger Prize, for Minimum Colour Vision Requirements for Professional Flight Crew. German Academy of Aviation and Travel Medicine · 2011
- Arnold D. Tuttle Award. Aerospace Medical Association · 2009
- Walsh-Weston Award. Society of Light and Lighting · 2008
If you have a question about visual function, we would be glad to hear about it.
We work with clinical and academic research groups, regulators and occupational health providers, and with companies looking to develop eye-related instrumentation or to license a validated test.