Unloading a supermarket shop from the boot of his car outside his house a few months ago, Zeke Iddon panicked as a stranger approached, seemingly out of nowhere, and grabbed one of his bags of food.

'For a second I thought someone was trying to steal my groceries,' says Zeke.

It wasn't a stranger at all - but his wife of 15 years, Julia, wearing a pair of sunglasses.

'I swore and momentarily considered yanking the bag back - but almost instantly she recognised what was happening and laughed,' adds Zeke, 41, a marketing manager from Dawlish, Devon.

'At that point I realised - ah yes, it's the woman I've been with for nearly 20 years.'

For Zeke, instances of mistaken identity like these are not uncommon.

That's because he is one of the estimated 1.3million Britons living with prosopagnosia, otherwise known as 'face blindness' - a neurological condition where individuals struggle to recognise faces, even familiar ones.

It's not a problem with vision, memory or intelligence, but rather a selective impairment in the brain's ability to process facial information.

People with face blindness see individual features, such as the eyes, nose and mouth, but lack the ability to integrate them into a coherent, recognisable face.

'While we typically take the face in as a whole, people with prosopagnosia tend to focus on individual features such as eyebrows because they can't take in the whole face,' says Dr Judith Lowes, a lecturer in psychology at the University of Stirling.

Zeke normally recognises his wife, a digital training specialist in her late-30s, because 'she's distinctively gorgeous and very tall - and generally in places where I expect her to be', he says. It was the 'big, movie star-style sunglasses' she was wearing that threw him off.

Prosopagnosia was first identified by the German neurologist Joachim Bodamer in 1947, who coined the term to describe patients who had difficulty recognising faces due to a brain injury.

This is now known as acquired prosopagnosia. Generally considered more common, however, is developmental prosopagnosia – where the disorder is not attributable to an injury. Instead, the ability to recognise faces appears not to have developed adequately in childhood.

Prosopagnosia 'affects an awful lot of people and it can be very debilitating,' says Dr Lowes.

She recently conducted a study of 29 adults with prosopagnosia aimed at better understanding what it's like to live with the condition, the results of which were published in PLOS One research journal last month.

Ten of the participants said that they could not reliably recognise immediate family members, and 12 couldn't recognise close friends in out-of-context or unexpected encounters.

'What we found from our research is that even people classified as having 'mild' prosopagnosia can have serious difficulties in daily life,' explains Dr Lowes.

'Many people spend an awful lot of time worrying that other people would think them rude. They were concerned about accidentally snubbing people - unintentionally ignoring other mums in the playground, for instance.

'Some of them found it difficult to build friendships because, of course, you have to build on those small social interactions. People talked about a rising sense of panic in a crowd and some deliberately avoided socialising in groups.'

Dr Lowes often likens the condition to having dyslexia.

'It's not a binary,' she says. 'It's not that people with face blindness can never recognise any faces. Most can sometimes recognise some faces, just like people with dyslexia can read some words.

'But it might take them longer and their brain takes a different route and makes more mistakes.'

A typical person will effortlessly recognise a familiar face in a matter of milliseconds.

But those with prosopagnosia 'tend to be significantly slower than average to recognise faces as well as being less accurate,' adds Dr Lowes.

Around 270,000 of those affected are children, the charity Face Blind UK says.

What's more, the condition often runs in families. 'You get mums with face blindness picking up their children with face blindness from school and that can cause difficulties,' says charity spokesman Hazel Plastow.

'We get people contacting us who are thinking of dropping out of university because they haven't made a single friend - it's hard to socialise properly when you walk into a room and don't recognise anyone.'

Zeke knew something was wrong from a young age – but couldn't pinpoint what.

'I have quite a large family with lots of cousins and I realised I was terrible at telling them apart,' he says.

'I would find myself getting embarrassed because I'd realise later that I hadn't been talking to the person I'd thought I'd been talking to.

'It must have been bizarre for my family - I was walking around calling people the wrong names.'

Zeke dismissed his difficulty with faces as no more than a quirk - until an occasion when he was 20 and working in a book shop.

'A very good friend of mine walked in to collect the book that she'd ordered,' he says.

'I asked for her name, and she was massively puzzled. She thought I was being rude, but I genuinely hadn't recognised her. She walked away rather confused, and I wondered why my customer was acting strangely.

'Her sister called me later asking why I'd been so rude, and I didn't have an answer.'

Zeke went to his GP shortly afterwards.

'I described what had happened and he told me I most likely had prosopagnosia. All the pieces fell into place.

He adds: 'I think people assume that I see everyone's face as some strange, gloopy mess. But it's not like that - I can see, but I know I won't remember it. I very much see it as a storage issue. My brain cannot store images of faces.'

Similar to others with the condition, Zeke relies on markers such as hairstyles, scent and clothing to recall who people are.

He found his wife's height helped him identify her from the beginning of their relationship.

'I'll let the armchair psychologists decide whether I fancy her because she's so recognisable, or whether she's recognisable to me because I fancy her,' he says.

At a party or dinner where he's unlikely to recognise people he knows, Zeke often relies on his wife to whisper in his ear who certain people are – but the workplace has brought more difficulties over the years.

'I worked in restaurants as a student and I'd go back to the floor with dishes and couldn't remember who to give them to,' says Zeke.

'Now, working from home is a piece of cake - I have scheduled meetings and know who I'm going to talk to in advance.'

Dr Lowes says many with prosopagnosia 'tend not to disclose it at work as workplaces are often unwilling to make accommodations'.

'People with face blindness are often mocked,' she adds. 'One of the most common responses that study participants told us about is others just laughing and thinking it's funny but it's really not, it can be incredibly stressful.'

Hazel Plastow thinks that it's crucial that awareness of the condition is raised - especially for children.

'This is a condition that can make children particularly vulnerable in everyday life and it's so under-diagnosed in schools,' she says.

Ms Plastow adds that people with acquired prosopagnosia - from a brain injury such as a stroke - also need better support, as they struggle for potentially different reasons.

'They've lost this ability which has been so automatic and that can be very disorientating,' she explains.

Not only is there currently no formal diagnostic process for prosopagnosia, there is no treatment either.

While developmental prosopagnosia is classed as a neurological disorder, Dr Lowes believes it should be considered a type of neurodivergence - a difference in brain function from what is considered 'typical'.

She points to a review of studies in 2023 'that found 30 per cent of people with autism would meet the threshold for prosopagnosia and about 80 per cent of autistic people have below-average facial recognition'.

Despite the fact that nobody else in his family has face blindness, Zeke was deeply concerned that his seven-year-old son might have inherited it.

'I was very worried and subtly tried to test it when he was younger,' he says. 'I watched to see if he recognised and gravitated towards familiar people. He's absolutely fine, thank God.

'It's not the worst thing in the world, but I wouldn't wish it on anyone.'