I can see clearly now

Goggles are "spectacles, often of coloured glass or covered with gauze: used to protect the eyes". So says my dictionary; and a skier or boarder wouldn't quibble with much of that, apart from the spectacles (I wear those under my goggles), the glass and the gauze. In the same paragraph the dictionary defines goggle as "to stare fixedly, as in astonishment", which is what I did after flicking through a catalogue from the French goggle manufacturer, Cébé. It showed 52 different types of goggle, some of them available in a choice of frame colours.

This simple device to protect the eyes from wind and snow – with, in my experience, the secondary function of misting up your spectacles so that you can't see anything – is available in more than 70 style and colour combinations from a single manufacturer. Add in the even larger range sold by Smith, an Italian company, plus those from Adidas, Oakley, Bollé, Carrera and others, and the choice is enough to make the uninformed buyer goggle-eyed ("a bulging stare").

Anyone looking for winter-sports equipment can bone up on the subject before going shopping. Ski magazines publish extensive, annual tests of skis and boards, with page after page of analysis of each model's ability to initiate turns of different radius on and off piste. Almost as much space is devoted to comparing ski boots; a less fruitful exercise since, as any good fitter will tell you, the choice of an appropriate boot is largely determined by the shape of your foot.

But I have never seen a buyers' guide to goggles. Small wonder then that, as a sales assistant in a skiwear shop told me, most customers at the goggle stand merely examine the stock, try on a couple of pairs, and then wait for someone to tell them what they're looking for.

For guidance on the key features of goggles, which range in price from about £20 to £125, I consulted Gemma Smith, accessories buyer for the retail chain Snow+Rock. She started with the basic, single-lens type without ventilation – cheap goggles "suitable for people who will only use them in emergencies, when conditions are really horrendous". These lenses will tend to fog up but more expensive goggles have devices which reduce that problem. Double lenses (like double-glazing) create a thermal barrier, keeping the inside surface warm enough to prevent condensation; hydrophilic coatings on the lens absorb moisture; and vents on the top of the frame let in a flow of air to carry away moisture, "just like a demister in a car", says Ms Smith.

On more expensive models, the lenses now have a curving, spherical shape, which offers greater peripheral vision without distortion: Smith promises a 180-degree field of vision, while Cébé makes the even bolder claim that wearers can "see what's going on both in front and behind". The spherical lens also increases the volume of air inside the goggle, which also helps to reduce fogging.

Frames vary in size, partly for aesthetic reasons, partly because it's important that your face fits. "The part which goes over the nose has to be very snug," says Ms Smith. "If it isn't, wind and snow can blow inside, which defeats the whole purpose of the goggles." Obviously, smaller goggles are made for children. And there are also more capacious frames for those who wear spectacles under their goggles.

Skiers and boarders who wear helmets that cover their ears also need a special type of frame. With the standard design, on which the strap is attached at the corner of the frame, the sides of the helmet can push the goggles away from the face; helmet-compatible frames avoid that by having the strap attachment pushed forward, sometimes on "outriggers". For obvious reasons, skiers and boarders who wear them should take their helmets and/or spectacles along when buying goggles.

The final variable is the choice of lens tint. All lenses should protect the wearer's eyes from ultra-violet rays (both Cébé and Smith claim 100 per cent protection); where they differ is in how they filter the colour spectrum. The standard tint, for use in bright or partly cloudy conditions, is a strong-filtering grey, with a reflective mirror surface added for goggles worn in very sunny weather.

To improve visibility in lower light, an orange or pink tone can be added: it brightens up details and improves shadow definition. A pure orange lens lets in more light, and makes variations in the relief of the snow surface more apparent, particularly in foggy conditions. In very low light, when even a bumpy piste looks flat, a yellow tint brightens everything up – to the point where it can give skiers a headache.

You don't, however, have to buy a pair of goggles for each type of snow conditions. Some manufacturers sell replacement lenses. So, if you are careful (it's a tricky job), you can fit a lens to suit the day's conditions; if you are careless, you can buy a lens to replace one that you have scratched. Among the Smith brochure's notes on goggle after-care is the advice not to push them on to your forehead (because it's warm and wet up there) and the suggestion that snow-filled goggles should, once the bulk of the snow has been removed, be taken to the toilet and gently dried out under the hand-dryer.

That seems a bit excessive. But if I had a pair of Smith's top-of-the-range Cascade Turbo CAM series goggles, I might feel differently. Priced at £125, they have a micro-electronic fan, powered by batteries housed in a case on the strap, which blows out moisture to offer – so the manufacturer puts it – "the ultimate in fog-free vision". (The fan even has a high power setting for extremely moist conditions.) The goggles are helmet-compatible and have a clip system allowing a prescription lens to be fitted inside. Could be the answer to all my problems.

For stockists contact Cébé (01635 277260) and Smith (0161 428 9060). For more information, see www.cebe.com and www.smithsport.com