Super Sunglasses

Every triathlete should get into the habit of wearing sunglasses for protection," says Peter Slaney, a former triathlete, optician of 20 years and managing director of www.directsunglasses.co.uk. And not just on the handful of sunny days bestowed upon the UK every year, but every time you run or ride. Whether it's blazing sunshine, overcast, raining or even night-time, you should wear glasses to protect your eyes from ultraviolet light, insects, dust and debris.

If you doubt the wisdom of this, look at an elite race - almost all the competitors wear sunglasses. "They know that a great performance could be compromised by something as simple as a bug in the eye," says Slaney. More importantly, sunglasses will prevent overexposure to the sun that can damage your eyes. If you're a serious racer you might invest in several pairs of sunglasses that will suit a variety of conditions, but if you're a recreational triathlete, it's worth investing in a pair with interchangeable lenses.

The spec

Many sunglasses feature several interchangeable lenses for a variety of light conditions. From clear lenses to dark lenses with mirror coating, here's what to wear and when:

Category 1: Clear lenses and light citrus lenses are suitable for night riding or running, and when it's raining or gloomy. 

Category 2: Persimmon and lighter brown and grey tints are suitable for cloudy days.

Category 3: These are dark lenses for bright days. Many feature an iridium or mirror coating for greater contrast in sunny conditions. Check that category three lenses have full UV400 protection to block harmful UVA and UVB rays.

Quick fit

When you're buying shades, you need to do more than consider aesthetics, important as they are. The shades must also fit well: follow Slaney's advice to ensure a good fit.

The sunglasses must feel comfortable. Be aware that not all styles will be a good fit for all faces.

If the edges of the lenses are too close to your face, the sunglasses might steam up. Conversely, if the edges of the lenses are too far from your face, sunlight and glare might enter around the sides and top of the lenses. Make sure there's a small gap between your face and the lenses.

If you have a big nose, go for an adjustable nose bridge rather than a fixed bridge.

The arms should have rubberised grips to hold them in place against your head.

Go for wraparound lenses.

Try the sunglasses on while wearing your bike helmet to make sure they still fit well when you're wearing it.