is it worth it? : Ain't no sunshine when they're on

They may cost pounds 220, but then German designer Jil Sander's new range of sunglasses has the style and engineering of a top-of-the-range Audi

The competition is hotting up for sunglasses this season, with every design house launching new ranges as high-street shops produce stylish, cheap and adequate alternatives.

Jil Sander is a German designer who successfully combines understated style with Teutonic precision. So, it's no surprise that her first range of sunglasses has the engineering of a top-of-the-range Audi. They are a microcosm of European skill: designed in Germany, hand-made in France by optician-to-the-stars Alain Mikli, and presented in a beautifully understated case from Italy. "Jil advises Alain on what she wants," explains Marie Claude Issarder at Alain Mikli. "These sunglasses are the result of their collaboration, so you get the best of both worlds." Two designers for the price of one, now that's a bargain.

I showed them to a product-designer friend who went into fits of When- Harry-Met-Sally-style ecstasy over their small but perfect form. It's difficult to describe technological poetry, but here goes. They are speckled silver with a thin band of metal running through the middle of the frame, which thickens towards the outside edge so the sun can't get to your eyes from the side. The plastic bits that rest on the side of your nose twizzle for a perfect fit and screws the size of microchips hold it all together. It's like wearing a mini Clifton Suspension Bridge on your nose, but far more comfortable. The oval, dark green lenses flatter everyone (it's not hard to get friends to try on pounds 220 worth of designer specs) and the clarity of vision in bright sunlight is excellent. So, why are they so good? "This model is made from cellulose acetate with ceramic coating, which is new technology in sunglasses" says Marie Claude. "The lenses have UV 400 protection and are made from CR39 plastic."

Well, that sounds marvellous, but is it necessary to have Isambard Kingdom Brunel's life's work on your nose? "The most important thing is that they give you good UV protection," says Dr Louise Culham, head of optometry at Moorfields Eye Hospital. "UV 400 is the standard level of protection that sunglasses should have against harmful UV rays. You can get sunglasses with UV 400 protection for pounds 20, but CR39 plastic is good because it has properties which protect against UV rays. Basically, you should look for sunglasses which protect all around the eye."

Police make a good pair of black and chrome sunglasses at pounds 89.90 which look similarly hi-tech at first sight. But they are not really in the same league, although they are comfortable, stylish and would make a good, cheaper alternative to the Jil Sander marvels.