I’m watching telly when I notice a bright green blotch appear on the corner of the screen. I assume this is a glitch with the programme and continue to gawp until the advert break. I get up and make a drink, then realise the green blotch has followed me into the kitchen and has been joined by a red one. The blotches are similar to the imprint a lightbulb makes on your vision if you stare at it for too long, so I ignore it.

The blotches multiply until a whole shimmering spectrum of colour zigzags across my field of vision until it completely blinds me. My passivity is replaced by blind panic. Have I been drugged? Am I having a stroke? I ask myself as I feel my way to my local A&E. By the time a doctor sees me, the spectrum has faded, and I can see. The doctor tells me that my vital signs are normal and that I probably had a migraine.

“A migraine? But I don’t have a headache,” I protest. “Not yet,” the doctor replies dismissively. The doctor notices the anxiety creasing my face. “Well, it could just be in your eye,” he says as he ushers me out of the treatment room.

A retinal migraine is a condition that causes brief episodes of blindness or visual disturbances in one eye. The Migraine Trust states that one in seven people suffer from some sort of migraine, but retinal migraines are quite rare, affecting one in every 200 migraine sufferers, and usually occur when blood vessels constrict in the back of the eye. Dr Katy Munro, a GP and headache specialist, suspects that I had a typical migraine with aura rather than a retinal migraine, as when I closed both my eyes, I could still see the shimmering pattern. If I was having a retinal migraine, the pattern would have disappeared when I closed the eye that was having the migraine. “Migraine aura is not dangerous. It’s uncomfortable and it’s quite debilitating and alarming when people get it because sometimes it comes on quite suddenly,” Munro says.

During a true retinal migraine, which produces the kind of patterns I saw, the spasming blood vessels at the back of the retina can lead to visual damage. “Sometimes there’s a kind of stroke that can mimic retinal migraine called amaurosis fugax – which means a fleeting visual disturbance – and that’s micro clots passing through the blood vessels,” Munro explains. “That’s why we would always urge people to go and get checked out by an eye specialist.”

‘I had this kind of arch of light in my right eye again. It looked like the Pink Floyd album ...’ Photograph: Posed by model/PA Media

I’ve experienced three migraines with aura since my visit to A&E and, so far, have not had an accompanying headache. For others, the pretty light show is merely a forewarning for the pain to come.

“I get lovely, sometimes jagged, black-and-white patterns. Sometimes I get rainbow patterns. They are quite attractive to look at, except you know what’s coming,” says Michael Pidd, a former professor at the University of Lancaster. Pidd started having migraines with aura in his late 30s. They began with a disturbance in his visual field followed by a severe headache. There used to be gaps of up to two years between his migraines, but in recent years, Pidd has been having them as frequently as one every 10 days. “The pain has got less over the years; it’s just feeling wretched, feeling low – a bit like feeling hungover but without any of the previous pleasure,” Pidd says. He keeps a diary of his migraines but hasn’t been able to identify their triggers: “These things can just kick in at any time. I wish there was a pattern. I wish it was due to drinking too much or not sleeping, or too much chocolate or whatever, but there’s no pattern and I’ve got about 10 years of records.”

Jane Bedford McLaren, a 40-year-old lawyer from Manchester, had her first migraine with aura while she was studying for A-levels, but experienced no headache. “Everything became pixelated in my right eye. It happened while I was in a lecture,” McLaren says. “I carried on as normal. I was just like: ‘This is curious.’ I think I was more concerned about not making a scene at that point. I sat there and just rode it out.”

McLaren didn’t have another migraine until 2015. “I was at my parents’ house looking at a computer screen when the bottom right-hand corner of my vision was disturbed again – as if it was pixelated.” This time a severe headache followed.

McLaren’s most recent migraine hit her two weeks ago. “I had this kind of arch of light in my right eye again. It looked like the Pink Floyd album [Dark Side of the Moon],” McLaren says. “It was like a thin line of fractured rainbow light. While I was on the train to work it went away, but then I got a really bad headache. That wiped me out for three days.”

Migraines and their auras have been giving the people studying them a massive headache for centuries. Today, scientists are still not sure if the true cause of them is primarily physiological or psychological. This is probably because research into migraines has received the least amount of public funding of any neurological illness in Europe. “Just because there’s no obvious explanation, they’re just not taken that seriously and people are denounced as attention-seekers or lazy or unable to cope. What we’re not getting to grips with as a society is this huge burden of chronic pain,” says Katherine Foxhall, a historian of medicine and the author of Migraine: A History.

When treating retinal migraines, doctors may prescribe painkillers and medications to relax and stop blood vessels constricting. The advice around preventing them, as well as migraines with aura, is mostly concerned with things that you should already be doing, such as not smoking, avoiding caffeine and getting enough sleep. Brains that are susceptible to migraines are more sensitive to change, so maintaining the humdrum of your life is probably advisable, too. “It’s really about keeping your brain in a nice relaxed regular routine as far as possible,” says Munro. “Make sure that you’re having a good routine. If you have a long gap [between meals] then you’re much more likely to irritate your brain and get a migraine.”

The problem I have is that I don’t have an established routine. So, if I do establish one, that will dramatically deviate from my routine of not having a routine, and therefore increase my chances of having a migraine. This is giving me a headache.