If you are booking a lie detector test in the UK you will be offered one of two things: a traditional polygraph, or EyeDetect® eye-tracking. They are trying to answer the same question by very different routes, and the practical differences matter more than the marketing.
We use EyeDetect®, so we have an interest here — which is exactly why this page sets out what a polygraph does well too. Choose on the merits, not on whoever answers the phone first.
A polygraph measures the body's stress responses. Sensors are attached to the chest, fingers and arm to record breathing, pulse, blood pressure and skin conductance while a trained examiner asks questions aloud and later interprets the charts.
EyeDetect® measures involuntary eye behaviour instead. A camera records pupil dilation, blink patterns, reading behaviour and response times while you answer true/false statements on a screen. Nothing is attached to you, and the data is scored by algorithm rather than interpreted by the person in the room.
Both methods, properly run, sit in a similar accuracy band — the mid-to-high 80s and low 90s depending on the question format and the study. Neither is infallible, and neither is automatically admissible in a UK court.
A skilled polygraph examiner can adapt during the session, follow up on a reaction, and cover a longer or more exploratory set of issues in one sitting. In investigative interviewing, that flexibility has real value.
Polygraph testing also has a defined statutory role in the supervision of certain offenders in England and Wales, so in that narrow context it is the established method.
For most private clients — infidelity, disclosure work, family disputes, false accusations, workplace theft — EyeDetect® is a better fit. It is quick, it is standardised, it is far less intimidating for someone who is already upset, and because scoring is automated there is much less room to argue that the examiner steered the outcome.
It also travels well. We can run examinations in a living room or a small office with no set-up drama, which is why we can offer same-day results at your home anywhere in the UK and Ireland.
Whichever method you choose, ask the same things: what exactly will be asked, who writes the questions, what accuracy figure they claim and where it comes from, what the total price includes, and what happens if the result is inconclusive. Anyone who promises a certain outcome or refuses to put pricing in writing is not the right provider.
Both sit in a similar band when properly administered. EyeDetect® is 86-88% accurate on validated question sets; well-run polygraph testing reports comparable figures. Neither is 100%.
Considerably. The EyeDetect® examination is about 30 minutes, where a polygraph session commonly runs from 90 minutes to three hours.
Prices are broadly similar; UK private tests typically run from around £400 to £800 depending on provider and travel. Ours is £495, or £800 for a couples test, with no travel charge within 50 miles of Darlington.
General nervousness is normal and is accounted for in both methods. EyeDetect® is less exposed to it because it measures eye behaviour linked to cognitive effort rather than physical arousal.
Neither is automatically admissible in civil or criminal proceedings. Any weight given is at the court's discretion, so take legal advice before relying on a report.
For most couples EyeDetect® is the more practical option: shorter, non-invasive, computer-scored and available at home the same week.
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