LISA FITTIPALDI crosses the road. She wears dark glasses and flicks the kerb with a white stick. She needs help from her companion, who warns her of an approaching pick-up truck.

In a building on the other side of the street, she pushes open an unlocked door. Resting against a table is a huge canvas of a group of flat-capped workmen. By the far wall, a white-haired conductor waves his baton at a still-shadowy orchestra. On the easel, a young woman combs her hair in a mirror.

Lisa cannot see any of these, just as she has never viewed the vibrant group of dancers that hangs on her dining-room wall, but she is intimately familiar with all four. After all, they are her own work.

There have been blind artists before, even artists who have gone blind. This is different, however. Lisa Fittipaldi is a rising star in the art world. Her work is sold through the biggest gallery in the United States and routinely fetches thousands of dollars. Many of those who buy her work are unaware that the artist has never seen it.

Or, as she puts it: "I want to be known as an artist who happens to be blind." Not that she is completely sightless, of course. Fewer than two per cent of the registered blind are.

But the degenerative disease from which she suffers has taken a heavy toll. She can barely distinguish day and night. Too much light gives her migraines. Too little creates a snowstorm in front of her eyes. She can just make out movement, but only if it is a few inches from her face.

The story begins seven years ago on a highway in Texas. "I was driving down Interstate 35 and suddenly the truck in front of me vanished. A few seconds later, it came back. A couple of weeks later, it happened again."

This time, it was a narrow miss with a juggernaut and her sight did not return. Lisa managed to pull on to the hard shoulder and, distraught, called her husband. Within a few months, she had been diagnosed with a rare degenerative vascular disease, one that had already killed her mother and a brother. Doctors attempted surgery and, when the bandages came off, she could indeed see again. Within 48 hours, though, the darkness returned. It has never lifted.

Before her illness she had been a successful chartered accountant, and before that a registered nurse. After a less than prosperous upbringing, she describes her goals growing up as: "To be financially secure and not live in poverty." The new reality brought on both an emotional and physical collapse. Worse was to come. A year later, her husband collapsed while visiting relatives and needed emergency open-heart surgery.

"Until then, I had taken to my bed," she remembers. "My husband was sick and I had alienated just about everybody who had tried to help me. So I got up, hopped on a plane, and took myself to San Diego. And everybody was saying, 'You can't do that.' All I could think was that my husband might die on me."

The shock jolted her back to life. As her husband recuperated, she made plans. "I figured I would do a sculpture class, play bridge and take up golf. Then the class was cancelled, nobody wanted to play bridge, and I found out that I was allergic to grass."

Back to square one, she slipped into depression once more. Then, one afternoon, her husband, back on his feet, picked up a child's watercolour set at the local Wal-Mart.

"He came home, threw it on the bed and said, 'Here, do something.' And I thought he was totally selfish and an S.O.B to boot."

Her first effort still hangs in the sitting-room. It is four glass jars, each overlapping the other, and with the vibrant colours that have become her trademark. Then she entered a local competition for the visually handicapped - and won an award.

Encouraged, she persevered. Initially, she did abstracts. "People would say you can't be an artist unless you can paint animals. So I painted an animal. Then they said you can't be an artist unless you can paint architecture. So I painted architecture. Finally it was, you can't be an artist until you paint people. A lot of my painting has evolved out of 'You can't.' "

It was her husband who signed her up for a street-crafts fair in Fort Worth, the biggest in Texas. "I sold my first picture and it was to one of the judges. I had no idea how much to charge. So he said that, for a work like that, a thousand dollars would be fair. A thousand dollars!"

Her face erupts with pleasure at the memory. Although in her early fifties, she has a childlike quality, emphasised by tiny hands and feet. There is nothing fragile, though, about her work, which ranges from bullfights to memories of her grandfather playing the piano.

Her work, inevitably, draws from the past. Fortunately it is a rich source of material. Although born in America, she was raised by grandparents living in London, first in Whitechapel, then Tottenham, Golders Green and Covent Garden. Later the family moved back to America.

Her grandfather was a powerful figure in her life. "We went to places like Petticoat Lane. Once he got up at 4am to show me the flower ladies in Covent Garden. Although he was Jewish, he felt strongly that you should try every religion. So we went to Westminster Abbey and a Baptist church near Blackfriars, even a Shinto temple." All this she recalls "almost as if it were on video tape".

A photographic memory is clearly the key to her ability to paint unseeing. Her technique is to work on six canvases at a time, sketching out the figures and shapes using a mental grid. At any time she knows exactly what is in front of her and where.

Colours are another matter. The paints are rigorously organised in drawers, separated by plastic dividers. When working in acrylic and watercolour, the texture also offers clues. "Red feels grainy. Cobalt blue is sticky. Yellow is lighter."

Before starting work, she groups the paints and brushes around the easel. There are two palettes, one just for flesh tones. Once a month, her husband checks that the tubes are still in order.

It could be, she acknowledges, that what leaves the studio may be totally different to the picture in her mind, "since I can't see it and nobody's ever said anything". There have also clearly been whispers that her vision is better than she admits, since she has copies of her medical files near at hand for inspection.

In a little over four years, she has progressed from street fairs to gallery shows. She has sold more than 400 works and now charges up to $8,000 per canvas. The proceeds were enough to buy a large Victorian house in downtown San Antonio, near Davy Crockett's famous last stand at the Alamo. The couple run it as an elegant bed-and-breakfast and are building a studio in the garden.

Last year she agreed to an exclusive contract with the Wentworth Galleries, the largest in America. There was one condition, that she switch to oils.

When the gallery owner broke the news, her reaction was: "What is he thinking about? Doesn't he realise I can't see!" Oils are apparently more difficult because they lack the textural distinctions of watercolour. "It's a bitch," as she puts it. They are also much slower to dry, so she must take extra care not to cover her clothes, and anything she touches, in paint.

The future is uncertain. On the one hand, she is achieving success beyond her dreams. President Bush has nominated her as one of his outstanding Texans, and she was recently a guest on the Oprah Winfrey show. She has also started The Mind's Eye Foundation, a charity to help visually impaired children.

On the other, the disease is getting worse. Her hearing is deteriorating and her speech is slightly slurred. In the end it will kill her. Still, for now there are oils to master. She also wants to improve how she paints buildings. "In the end, I think I will be a fabulous painter," she says. "For now, I'm still learning."