I have worn glasses for just over 10 years. I was lucky. It wasn't until I was about 17 or 18 that my eyesight started to wane, which meant I never had to suffer the indignity of childhood spectacle wearing and the compulsory bullying that came with it. In fact, by the time I was aware that boys don't make passes at girls who wear glasses, I had enough other tricks up my sleeve for it not to matter.

As a result, I have never had a problem with wearing glasses; in fact, I always rather enjoyed it, not least because needing glasses meant that suddenly my eyes became a whole new area of the body that I was free to accessorise at will. It wasn't until I saw a picture of myself wearing my first pair of glasses that I realised the devastating effect of picking the wrong pair of glasses. Round-rimmed tortoiseshell, for goodness' sake. I wish I could remember what possessed me.

"The shape of the frame should counter the face," says Michael Jawett, of Marcolin UK, whose brands include D&G eyewear and Chloé Lunettes. So people with square faces should go for round frames, those with round faces for square frames, and so on. Generally speaking, in terms of size, slimming oval shapes should be worn by people with large faces and large plastic frames should be avoided by those with smaller faces.

And where does tortoiseshell fit in? Nowhere, unless you're a tortoise. Not only did I pick the wrong shape, but also the wrong colour. My mistake was going for something far lighter than my own skin tone - people with dark skin should stick to dark frames. "Neutral classic tones such as honey and caramel will suit fairer complexions, whereas darker tones can get away with dark-coloured lenses," advises Nina Flintham of David Clulow. "Gold frames and diamanté detailing work well on black skin."

"Shades to avoid would be pastels and powder colours, such as lemons and pale pinks," says Flintham, kindly omitting to mention tortoiseshell. And no, it wasn't real.