In today's health-conscious society, consumers are allocating an increasing amount of money to active holidays, winter sports and gym memberships, not to mention the latest hi-tech footwear and designer sports clothing. This lifestyle trend has also been noticed by the eyewear industry, a fact demonstrated by the growing range of sports eyewear products designed to enhance athletic performance that is now available in the marketplace.

"When a person participates in sport - whether it's for relaxation, to keep fit, or just for fun - he's always looking for ways to progress," says Gilles Demetz, owner of Demetz Optique de Sport, a French optical chain specializing in sports eyewear. "And to enhance his performance, not only does he have to train, he has to arm himself with the right gear - this includes having the correct equipment, footwear, and clothing as well as eyewear."

The sports eyewear market looks a promising one, with an estimated 60% of Europeans taking part in at least one sporting activity and one in two patients entering a practice being a potential sports eyewear customer. Furthermore, one doesn't have to be a sports vision specialist to be able to advise customers on quality sports eyewear. With a little homework on the different lens options available and some strategic questioning, optical retailers can offer their customers a personalized product.

"As more and more sports enthusiasts demand eyewear that is made to measure, the optician must be able find the most appropriate lens materials and treatments and tailor them to the customer's sporting needs," says Mr Demetz.

• Materials -

Because of its impact-resistant properties, polycarbonate has become the firm favourite in the design of sports eyewear, particularly for racket sports such as tennis and squash. It is also popular for outdoor activities such as cycling and hiking. While the material's optics have posed some problems for certain sports, such as target shooting, recent improvements to the material have cleared up the peripheral distortion.

Another safe lens option and a worthy contender with polycarbonate is PPG Industries' Trivex. Like poly, the material is impact resistant and lightweight, but it has a higher Abbe value which gives it the advantage of less chromatic aberration.

• Tints -

The colour and intensity of the lens tint plays a very important role - not only does it provide protection against the light for outdoors sports, but it also enhances contrast and improves visual perception," says Mr Demetz..To find out which colour tint would be most suitable, you need to ask the patient about the colour scheme of his sporting environment."

THE POPULAR CHOICES OF TINTS ARE:

Brown or amber - The lens colour of choice for sports where high glare is experienced, such as skiing, sailing, rowing and angling. It allows excellent contrast and its dark colour minimizes eye strain. Effective for absorbing blue light waves, it sharpens visual acuity, and improves depth perception and contrast in variable light conditions.

Vermilion or rose - A general-purpose tint that heightens visual acuity and enhances colours. Like amber, it is effective in filtering scattered blue light and improving contrast. It delivers the brightest field of vision and is suitable for skiing and angling, as well as all low-light conditions.

Yellow - A standard in skiing and shooting sports, yellow provides good depth perception and contrast in low light.

Grey - A neutral colour that provides natural contrast and the least amount of colour distortion of any lens colour. While it doesn't improve contrast, it is ideal for golfing, water sports, marine activities, driving, flying and beachwear.

• Coatings - The choice of lens coatings is also crucial to the visual comfort of the wearer. Antiscratch coatings are often the norm for sports lenses made from polycarbonate due to the material's 'soft' nature. Antireflective coatings, when applied to the back surface of a sun lens, minimize back glare. When paired with an easy-to-clean, hydrophobic coating, they have the added advantage of preventing sweat droplets from remaining on the lens surface. Mirror coatings reflect light away from the eye and can be applied to the outside surface of the lens as well as over any base colour.

Those who participate in sports with changing light conditions appreciate:

• Photochromic lenses - the adaptable depth of tint of photochromics, and particularly the improved speed of change in the new-generation photochromic lenses.