His wife Michelle, a 47-year-old college tutor, described what happened.
"What was meant to be a quick meal out with David turned out to be one of the most frightening times we've had," she said. "We had our starter which wasn't very good but we ate it and didn't tell the waiter.
"When our mains came and the meat was like what I can only describe as rubber, we told the young waiter when he came and asked us 'how is your food?' that the meat was very tough and rubbery.
"To cut a long story short the chef came to our table he was extremely rude and aggressive and accused us of not wanting to pay for our food.
"We said we would eat the rest of our food but the meat was really not eatable.
"He started swearing at me so David said 'there's no need to swear at my wife'. The chef caused quite a scene and was shouting and swearing so David walked back to the kitchen door with him asking for an apology.
"The chef came to the door with a large bowl of chilli powder which he threw at David's face.
"He instantly thought he had been blinded and didn't know what he'd thrown at him, he was shaking in chock, hanging on to the counter being sick thinking he was going to go blind.
"It was horrific. He said he's never had so much pain in his life and was extremely distressed.
"Not one member of staff came to him to help or even ask if he was okay.
"We were in the toilet splashing water on his eyes until the police and ambulance came he was treated straight away in A&E. "
The couple were taken from Prince of Bengal in Tonypandy, Rhondda, South Wales, to hospital for treatment.
Mrs Evans, of Tonypandy, said: "David had numerous eye washes through a drip into his eyes in A&E as his eyes were extremely red and sore and the pH level was way off what it should have been and the doctor said if he wasn't treated it was very dangerous for him.
"The chilli had even burnt the skin on David's hands and chest where the chilli had fallen down his shirt.
"He has to be on medication for his eyes until the doctor can see an improvement. We can't believe this has happened and have since read some bad reviews about this man.
"We want everyone to be aware of this and what has happened and are taking it further with the police."
The couple are parents of West End singer Sophie Evans, 23, who was runner-up in the 2010 series Over the Rainbow which aimed to find a new star for Andrew Lloyd Webber's Wizard of Oz – and she went on to play Dorothy.
Mother-of-two Mrs Evans said her husband is having specialist check-ups and is taking steroid eye drops to suppress his body's severe reaction to the chilli.