The vast majority of Britain's 14.4million female motorists admit to putting style before safety, research shows.
But road safety experts say they should jettison the chunky wide-armed variety of sunglasses worn by Kylie Minogue, Paris Hilton and Victoria Beckham - as well as those with pink or very dark lenses.
The Eyecare Trust charity also advised women to make safety their first priority with sunglasses for driving.
More than eight out of ten women (82 per cent) surveyed failed to consider safety when choosing sunglasses for driving - equivalent to 11.8million female motorists.
One in ten - 1.3million - drive in wide-armed glasses that severely restrict their peripheral vision. A further 7 per cent wear lenses that are so dark they are illegal for driving.
The researchers commissioned by insurer Sheilas' Wheels also found that fewer than one in five (18 per cent) of women bought sunglasses specifically for driving while almost two-thirds (61 per cent) based their choice on appearance rather than practicality.
More than half (57 per cent) want better labelling and more information in shops on which are the best styles for motorists to buy.
Niki Bolton, of car insurers Sheilas' Wheels, said: "Too many women drivers are unaware of the dangers of wearing some of this summer's hottest sunglasses' styles when driving.
Wide arms and dark lens tints may be the must-haves of the moment, but fashion- conscious women should put safety ahead of style when in control of a car."
The Eyecare Trust examined five styles of fashionable sunglasses and found that only two weresuitable for driving.
Trustee Rosie Gavzey said the darkest shades fail to allow a minimum proscribed eight per cent of visible light through and are illegal.
Pink tinted lenses can make it difficult to read road signs or spot hazards by distorting colours and wide-armed glasses create blind spots.
Aviator style glasses that curve around the eyes and have slim arms are recommended, along with anti-reflective lenses coloured in neutral brown or grey shades.
Mrs Gavzey said: "Chunky frames could pose a hazard when driving. Motorists need good all-round vision and a visual range of at least 120 degrees.