Taking a simple online questionnaire could tell you whether you have a condition commonly known as 'face blindness' – or prosopagnosia.

Characterised by an inability to recognise faces, prosopagnosia is thought to affect between 1-2% of the population, although too few studies (involving only small number of participants) have been conducted to date to confirm these figures.

Those affected have to rely on clues such as hairstyle or voices to identify who they are talking to – and to avoid embarrassing situations, many confide that they tend to avoid social gatherings.

There has been more awareness of face blindness in recent years, especially since actor Brad Pitt opened up about having the condition. However, many doctors still don't know much about it, and scientists are still struggling to document it.

"The best solution at the moment for patients is to get in contact with researchers who have an interest in studying the condition. We don't know enough about it, we are in the earliest stages of investigating it", researcher Punit Shah of Anglia Ruskin University told IBTimes UK.

Shah led a study recently published in the The Quarterly Journal of Experimental Psychology, which shows that a quick online test designed with prosopagnosia sufferers can provide people with accurate insights into their face recognition abilities.

Do you have prosopagnosia? You can take the test here.

More research needed

This simple questionnaire is based on lengthy interviews with patients discussing their daily experiences and on face processing theory. It asks participants about the extent to which they agree or disagree with 20 statements, such as "I often mistake people I have met before for strangers" or "I sometimes find movies hard to follow because of difficulties recognising characters".

In the new study, the scientists compared the scores obtained by prosopagnosia sufferers with results from in depth computerised face recognition tasks. This includes tests in which participants have to recognise same faces from different angles or the faces of famous personalities – those worse affected by the condition struggle even to recognise celebrities like the Queen or Barack Obama.

The findings of the study suggest that people do have insight into their own face blindness – with moderate-to-strong and statistically significant correlations between the questionnaire's scores and the results of computer tests. They confirm that this questionnaire is a simple and effective method of diagnosing the condition. It could be a helpful tool to use on a larger scale in future research.

The scientists hope that this study will raise further awareness of the condition and prompt people who believe they are affected to get involved in their research.

There is still much to do. Shah is planning studies with larger samples to better estimate the condition's prevalence. Investigating what might be causing this in the hope of one day finding a treatment will also a priority.

"We know that prosopagnosia does run in the family, sometimes entire families are affected. So there is an indication that there is a genetic element to it but have been unable to identify it because would need much larger samples", Shah concluded.