What's the real cost in use?

When buying safety eyewear, companies often base their decision almost entirely on the price tag regardless of the brand. But there is one important factor that is worth remembering - apart from the quality, durability, comfort, style and effectiveness of the product - it is the real cost, by which we mean the cost when in use that determines the value and quality of that purchase.

Safety eyewear is subject to a series of optional tests, under European Standard EN 168:2001, which covers non-optical test methods on personal eye protection. Under this standard, lenses may be tested for resistance to surface damage by fine particles and carry the symbol ‘K’ (alongside the CE mark supplied by the manufacturer if they meet this requirement). They may also be tested for resistance to fogging, where the lenses must remain fog-free for a minimum of eight seconds when exposed to an atmosphere above 50 degrees C. Lenses that meet this standard are marked with the symbol ‘N’. It is important to ensure that safety eyewear meets, or preferably exceeds, this voluntary standard.

As part of our ongoing research and development into lens coatings, uvex recently conducted in-house tests on the durability of the lens coatings of our own and other manufacturers’ safety glasses by repeatedly washing them to see how quickly the anti-fog coating deteriorated. This is based on the assumption of two washes per week through 44 weeks per year.

The average spend per person shows that the user of the safety glasses costing £2 each would go through 22 pairs a year, costing an average £44 per person, while those using glasses costing £6 per pair would only need 3.6 pairs in a year because the anti-fog coating lasts indefinitely – total cost £21.60 per person per year.

The convincing results of the test demonstrate the benefit of considering the product in more ways than just the price per unit. By taking a wider view and thinking about the real cost of the product over a period of time, a simple calculation can be done to ascertain the 'cost in use' or value of the product over the annual use of an average person.

Protective eyewear is often used in harsh working environments, so the lenses are usually coated to increase their efficacy and longevity. This coating is more important than you might think and is a key factor in ensuring the eyewear is worn - and protecting the wearer. For maximum effectiveness, lens coatings should offer resistance against fogging and scratching.

Coatings can be either:

• hydrophobic (moisture repelling) detergent-based coatings (which can be washed off) or
• hydrophilic (moisture absorbing).

A hydrophobic coating repels moisture which ultimately leads to a build up of perspiration on the lens, which in turn requires cleaning to remove it. Eventually, depending on the quality of the coating, the detergent properties will be washed from the lens, rendering it ineffective.

Hydrophilic coatings can be produced that are permanent and do not wash off. The coating becomes sponge-like, absorbing moisture so that the wearer does not have to take off their glasses or goggles to clear any fog.

Learn more about uvex lens coating technology