"You can imagine how terrified I was. I just wanted it all to go away. I'd end up wide awake, in floods of tears," he told the MIrror UK.
He said as an adult, episodes have been linked to times when he is under stress, the last one taking place when he was changing jobs in October.
"They last about a minute. I used to dream about these episodes as well, and then wake up experiencing them, which is weird.
"You can also experience AWLS with your eyes shut - shutting your eyes doesn't stop the sensation in any way.
"You could be gazing at an object, like a painting on your living room wall, and then suddenly it pops right up in your face. It feels like the room is caving in on you.
"Even if you're brain is saying: 'no, we've been here before, this isn't real,' your perception is that this is so real. It's the strangest feeling."
He experiences the reverse as well, feeling as if he is in a vast space with objects appearing like tiny dots when in reality they're just metres away.
Few studies have been conducted on the condition, but researchers tend to agree symptoms usually begin to manifest in childhood and can be linked to migraines and epilepsy.
Williams says his condition doesn't stop him living a normal life and he is usually affected at night, just as he is going to sleep. He has tactics to lessen attacks such as holding his hands close in front of his face to re-focus his vision.
With relatively little information about AWLS, he has created a Facebook page to connect with other sufferers and share any new research findings.
"With AWLS, I'd just love to find out more about it, are there scientific studies being conducted on this condition? Because let me tell you, it really truly exists."
- nzherald.co.nz
