Ian CollinsFlashback or flash of looming migraine? IAN COLLINS looks at the dazzling work of Bridget Riley since the 1960s, ahead of a major Norwich exhibition, for as long as his eyes will allow.Ian Collins

Flashback or flash of looming migraine? IAN COLLINS looks at the dazzling work of Bridget Riley since the 1960s, ahead of a major Norwich exhibition, for as long as his eyes will allow.

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With the death of 'Spiderwoman' Louise Bourgeois, in New York aged 98, who is the world's greatest living female artist? Some will name the woman whose exhibition opens in Norwich tomorrow. Others will complain that the long career of Bridget Riley has got on their optic nerves.

For this is the mistress of Op Art who, having trained at London's Royal College of Art in the mid-1950s, with the similarly stellar likes of Peter Blake and Frank Auerbach, developed her eye-popping style around 1960.

Several years before the Rolling Stones told us to Paint It Black, she was doing just that - with monochrome geometric patterns designed to explore the dynamism of sight and disorientate the eye.

Looking at the contorted and distorted black and white grids of Riley prints and paintings, many felt dizzy and giddy.

Some thought of the fuzziness they were forced to face while trying to tune in a pre-colour telly. Others recognised their suffering as seasickness - while sturdier, or more enlightened, souls compared their sensual exhilaration with skydiving.

Op Art equals Optical Agony? Well, as a brilliant guide said to the more nervy members of our group, as we toured the Hampstead home of brutalist architect Erno Goldfinger at the weekend and came upon a wobbly whopper by Bridget Riley in the dining room: 'Don't panic and it will all calm down!'

There is even a comic touch in the title of the show about to hit Norfolk: Flashback. Those who wander into the art gallery unawares, after savouring the stuffed animals and the Boudica experience, may think they are seeing the jagged lightning flash of an imminent migraine.

Best to see - and judge - for yourself.

The idea of this Hayward Touring Exhibition is to set works bought by the Arts Council from the early 1960s with more recent pictures - four of the latter coming from the artist's own collection.

The timing is perfect. The show complements the Castle's ongoing blockbuster of pop photos - Beatles to Bowie: The Sixties Exposed. Look again at the black and white umbrellas John and Paul are holding slightly askew over the heads of the Fab Four in one of the snazziest snaps - pure Bridget Riley!

But there was something magisterial about the first lady of British painting even when first emerging on to the art scene. She is descended from Gladstone and retains a natural authority - being a compelling speaker and writer and curator for her work and that of others.

The touring exhibition consists of eight large paintings and 30 works on paper. Actually, the Arts Council owns only one Riley oil from the 1960s but Movement in Squares, of 1961, is the most famous one of all.

Looking at it - for as long as the eyes will allow - and at other borrowed works from that soon-to-be-swinging era, it's not so much the optical impact that's the problem for me, but the memory of what came later.

I suddenly expect to see a gun and corpse, or maybe Twiggy in a mini, imposed upon what will become a merely decorative backdrop. Exploitation of her Op works for commercial purposes caused Riley to look elsewhere (though she herself had worked as an illustrator for an advertising agency until 1964).

She turned to colour in the flower-power year of 1967, by producing her first stripe painting. The Arts Council has a firecracker from 1985 called Ecclesia.

From exploding cogs, dissolving chessboards and unravelling herringbone patterns she has moved through bright stripes to kaleidoscopic patchworks and curlicues, rainbow jigsaws and Meccano kits. She herself has spoken of being inspired by memories of sun flickering on water in the Cornwall of her childhood or the hieroglyphs admired on an adult holiday in Egypt.

Throughout it all, Bridget Riley has remained an artist that other artists at home and abroad have been watching. Representing Britain at the Venice Biennale of 1968, she was our first contemporary painter - and the first woman - to win the prestigious International Prize for painting.

Then again, a fair few artists haven't just watched her, they have worked for her. For decades now our premier female painter has employed others to complete the menial task of painting while she concentrates on drawing the masterly designs.

As she says: 'It is as though there is an eye at the end of my pencil, which tries, independently of my personal general-purpose eye, to penetrate a kind of obscuring veil or thickness. To break down this thickness, this deadening opacity, to elicit some particle of clarity or insight, is what I want to do.'

And to get the assistants to do. It has been fairly pointed out that this practice has a precedent in the great workshops of the Renaissance. But a stickler might want to reclassify some of these weird or wonderful works as Studio of Bridget Riley.

t Bridget Riley: Flashback is at Norwich Castle Museum and Art Gallery until September 5.