A clip posted to a popular Facebook group for MAFS fans shows Josh speaking to producers during a recent episode.
After not realising the hidden detail before the clip emerged, one fan pointed out Josh had heterochromia – the presence of different coloured eyes. In Josh's case, his left eye is brown and his right eye is blue.
"Anyone else notice that Josh has heterochromia? I only just realised," a fan wrote on the Facebook page.
A number of others who failed to notice the unique trait flocked to the comments to share their shock.
"I didn't notice," one surprised fan said, followed by another who commented, "Only just noticed".
"Feel kind of stupid," a third added.
"Never even saw that, good spotting," a comment read, while another said: "OMG! You do pay attention."
Other eagle-eyed fans claimed they had noticed Josh's unusual eye colour as soon as he appeared on TV screens.
"My daughter has it so I noticed it straight away," one claimed.
"Yer it's the first thing I noticed," another commented.
"It's more common than people think," a third said.
Josh lashes out at bride Melissa
On Wednesday's explosive episode of Married at First Sight Josh lashed out at his bride Melissa Sheppard after they were set the challenge of sharing their goals for the next five years.
While Josh prioritised his career, health and children, his 'wife', a self-proclaimed "freak in the sheets", put healthy sex life towards the top of her list.
It caused tension between the pair after Melissa said, "I need that because that's huge to me".
"It's obvious when we put out our five-year plan that we want very different things," Josh told producers.
"I personally feel that you have sex as an extension of the way you feel about someone, it's not what you put on a five-year plan."
Melissa then confronted Josh saying she felt "rejected and judged".
"I didn't sign up for just a roommate, if I'm not having sex with you, I don't feel like I get anything else from you and it makes me not want to lie next to you," she said.
"You're probably looking for someone that's a bit more quieter and less needier in that situation than what I am ... I'm scared this is going to get very boring, very quickly."
Josh then told producers he was "f***ing out of my mind angry".
"I am a man and I'm not a f***ing disposable sex toy ... I didn't come here to meet someone to just f*** them all the time. If I wanted to do that there's dating apps for that," he said.
"I came here to meet someone, she did not come here to meet someone, she came here just to f*** all the time.
"It f***s me off that she keeps driving this narrative that I'm this super conservative guy. No, I'm not, and when I'm in private I will behave in a manner that's appropriate for husband and wife."
Josh told Melissa her sex drive was her "defining persona" and asked her if she knew what made his cup full.
"You have never showed any interest in learning anything about me ... What do I do for a job?" he asked.
"I don't know," Melissa responded.
"Oh my God," Josh said in exasperation.
Melissa then said they should take the sex out of their relationship to get to know each other on another level, to which Josh said he didn't think she could.
"Don't tell me what I can and can't do ... let's remove it and show me what Josh can do for me without the sex," she said.
Josh then announced he was going to bed and when Melissa said she would come and tap him goodnight, he said: "I'd prefer that you didn't, thanks."
Melissa was clearly annoyed by the situation as Josh then removed his wedding ring and placed it in a drawer.
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