To the uninitiated they are just sunglasses. But for wealthy fashion victims, Lapo Elkann's carbon fibre shades are a must-have accessory.

At £695 a pair, the glasses are at the pinnacle of the market in designer shades.

Made of one of the world's most advanced and expensive materials, they are extravagance taken to excess, something their creator knows all about.

Two years ago, Mr Elkann, 29-year-old scion of the car giant Fiat, was found in a coma after a drugs overdose, in the Turin apartment of a 54-year-old transsexual prostitute.

Despite the fact that he is grandson of Fiat patriarch Gianni Agnelli, Mr Elkann's career as the firm's brand promotions director came to an abrupt end. He spent six months in rehab. He has made a remarkable recovery, reinventing himself as a fashionable designer.

And his new sunglasses - the first offering from his Italia Independent label - have just hit London. His Sever line is the first to be completely handcrafted from carbon. Despite the price, the firm claims there is already a growing waiting list to get a pair. These latest must-have glasses highlight record spending on shades in a sector that will be worth more than £270m by the end of this year.

According to analysts Mintel, the sunglasses market has grown by 24% since 2001, outstripping the 13% growth in designer clothing during the same period.

Sunglasses are the new handbags, says Harriet Quick of Vogue. "The rise of the luxury accessory has spread to sunglasses, where it seems it's quite normal to spend £250."

But Jacques Basson from Polaroid sunglasses is unconvinced. "Carbon fibre frames, so what? We don't believe consumers are that gullible ... They want fashion, yes, but they want function too and they want value for money.

Would you pay £100,000 for a Ferrari only to find it's got a Fiat engine in it? No, so why pay nearly £700 for sunglasses that might be high fashion this season but don't deliver anything else?"

In an interview, Mr Elkann was bullish about his creation. "It takes eight hours of handwork and 47 layers of carbon and is a tailor-made pair of sunglasses. It is not distinctive - it's unique."

Creativity

He sees himself as an entrepreneur who bridges the worlds of fashion and creativity and says that he has begun with sunglasses because "every brand in world starts with a simple vision and what is better than eyewear?

I like to work with artisans. It's a totally different way of perceiving and bringing luxury to the market".

Mr Elkann is not shy of self-promotion and has managed to persuade pundits that he is a serious contender for Italy's best-dressed man. His style will be celebrated in a photographic spread in next month's US Vogue. But Mr Elkann's love of fashion doesn't extend as far as his competitors. "Huge logos are tacky and unnecessary. It is mass luxury and not distinctive luxury," he said. "A lot of the fashion brands only display their logo and that's all. They don't do anything incredible in terms of materials.

Often designer sunglasses like Armani, Gucci and Dolce & Gabbana are big licence agreements with companies that just put logos on a piece of plastic."

George Bamford at Bamford and Sons in London - the sole UK stockist for Mr Elkann's Sever shades - was sanguine about selling sunglasses for hundreds of pounds a pair. "This state-of-the-art collection is juxtaposed in our store with vintage collectibles - a true representation of the distinction and luxury we represent," he said.

"I don't think value for money comes into it when you're talking about designer items, " said Julie Sloan of Mintel. "Style is everything with sunglasses. "