The eyes have it

With such an abundance of styles and trends on the shelves, a fabulous pair of sunglasses is surely the easiest way to make an individual statement with your hot-weather wardrobe

Of all the items in your holiday luggage, the one thing no well-packed holiday suitcase should be without is a fantastic pair of really cool sunglasses.

But unlike your choice of sarong or flip-flops, the shades you sport can have a significant impact on your health. Happily, though, it isn't difficult to pick up a pair that protect as well as look stylish - provided, that is, you know what to look for when buying.

The UV rays that can damage your skin are also absorbed by your eyes. And in summer, it's not the increased amount of sunlight that poses the problem, but the circumstances in which we enjoy it. The highest levels of UVA and UVB are found reflected off sand and water - both constituents of a good summer holiday.

Exposure builds up in the eyes throughout life, and heavy doses can increase the likelihood of developing cataracts (where the lens of the eye becomes cloudy) and degeneration of the macula, (the central part of the retina) in later life.

So, just how can you be sure that your shades are blocking out everything you need them to?

Quality pairs should block 100 per cent of UVA and UVB rays, and will be labelled to this effect.

Look out for glasses carrying the European standard CE mark, which ensure that the sunglasses offer a safe level of protection. The filter category, which ranges from 0 to 4 with 4 being the darkest, is also worth noting. A rating of 2 is suitable for general use. While you might think a darker lens would offer better defence against harmful rays, it's not always safest to wear the blackest shades available, as your eyes may be confused by the darkness.

Darker tints may do more harm than good, because your pupils will open wider and let in more UV light. It's particularly important not to wear very dark glasses while driving - a really opaque lens will make it difficult to see the road and spot obstacles.

Once you're sure your glasses are safe, it's time to think about picking a style from the vast and mind-boggling array on display. High-fashion trends may not always be flattering, so be aware of what really won't suit you before you hit the accessories section. Consider your face shape and general colouring when picking frames - features such as a square jaw or a long forehead will determine your choice of style, while knowing whether your complexion is "warm" or "cool" will help you decide what colour glasses to go for. If you're still uncertain, try asking an optician's advice.

This season's sunglasses have a classic, glamorous feel. Wide-framed, oversized styles are particularly in, conjuring up images of Jackie Onassis or Audrey Hepburn, radiating mystique from behind a pair of huge shades.

Above all, have fun with your all-important accessory - designs are getting far more flamboyant and really adventurous, so make the most of the wide range available and add a real twist to summer dressing.