We have all seen sunglasses with mirrored lenses around, but does the mirror effect have a purpose in Safety glasses? Where did the idea come from? How are they made? Read on to find out.

What are Mirrored or flash lenses?

Mirrored lenses are standard lenses with a very thin reflective, often metallic coating added to the outside.

They can come in a range of colours but are not necessarily the same colour as the lens underneath and do not affect the colour that the wearer sees. For example, you may be wearing green flash glasses but do not see everything in green if the lenses underneath the coating are another colour, like brown.

When were mirrored glasses invented?

Eyewear with mirrored lenses has been around since the late 1940s when fashion resumed its emphasis following the war. Glasses began taking on many shapes and tints, the price of fashion eyewear went down due to cheaper manufacturing and sales went up. Mirrored lenses were initially a fashion gimmick. The first advert for mirrored lenses in 1948 appeared in the New York Times, stating “the wonderful fun of looking out at a world that can’t see you”. (Saks 34th St. advertisement for “Mirro-Lens” sunglasses, New York Times, 28 March 1948, p. 30).

Since then, mirrored lenses have continued to develop, and today you can see them in all colours and styles. Bollé Safety is a brand that keeps abreast of trends as one of the factors in the decision to wear safety glasses. As such, they feature mirrored lenses as an option in several products. However, they do also have a purpose…

What do Flash Lenses Do?

Despite being created for fashion purposes, mirrored lenses also help to protect the eyes due to their reflectiveness. This makes them useful in safety eyewear. Primarily, they reflect light, which is what gives them their mirrored appearance. As a result, less light enters your eyes, reducing glare and making things appear a little darker, much like ordinary lenses, but to a greater degree. This is particularly useful for those who are more sensitive to light or when the amount of reflected light makes things dazzling, like in maritime environments.

Flash lenses also reflect heat, which can be helpful in conditions where the hot sun is reflected into the eyes. Examples of such environments include mining, maritime and construction. 

Mirrored or polarised Lenses for Safety Glasses?

Often the two concepts are confused, but flash lenses are not the same as polarised lenses. However, polarised lenses can come with an additional flash coating, giving the wearer the benefit of both. A polarised lens is a standard lens into which a film of polarising filter material has been inserted. It works by only letting light that travels at a certain angle (vertical) through, which is generally about 50% of the light hitting it, blocking horizontally planed light. Reflected light is generally horizontally planed, which is why polarised eyewear is so good at reducing glare.

Mirrored lenses don’t work the same way: they don’t only let vertically planed light through and block the rest. They work by reflecting a portion of all light from coming through at any angle.  

So, whilst both flash and polarised lenses work to reduce glare, and both protect the eyes from UV, they do it differently and thus have slightly different properties.

Polarised lenses are arguably better at minimising the effects of pure glare. For example, when trying to look through the surface of the water to see what is at the bottom, they block all of the light reflected off the surface. Flash lenses reduce all light without specifying, so some glare may remain. 

However, polarised safety glasses can be a problem in some environments. They can make it hard to read electronic displays, LCD screens, & GPS displays such as those found in smartphones, cars, planes, and heavy machinery. In these situations, mirrored safety glasses would be preferable to a polarised pair. 

Moreover, in snowy conditions, being able to see the ice is necessary, such as when driving or skiing. In this instance, polarised glasses work too well, so it is often impossible to see the reflection that makes ice seen. Therefore, glasses with flash lenses are more appropriate as they minimise overall glare rather than all of a particular type.

How to look after Mirrored Safety glasses

Mirrored lenses are more durable than other lenses due to the additional layer protecting the lens underneath, but the reflective surface tends to scratch more easily, so eyewear with flash lenses needs proper care. Using substances like toothpaste, baking soda or scourers will scratch the lenses and should not be used. Likewise, rubbing alcohol or antimicrobial soap will cause damage. Trying to fill in minor scratches with car wax or oil will not only not fix scratches but cause visibility issues. The best solution for cleaning any eyewear is either a specialised cleaning solution, such as Bollé Safety’s B-Clean, certified by Colts Laboratory to do its job. Otherwise, plain soapy water and a soft microfibre cloth will clean your glasses without damaging them.

A rundown of Bollé Safety’s Flash models

Bollé Safety has a wide range of safety glasses, goggles, shields and accessories that aim to increase eye safety in any workplace by providing maximum protection, maximum comfort and maximum style. The range has an option for everybody, whatever their needs. Bollé Safety flash lenses come in silver, blue, green or red and come in a range of different frames and treatments. All of the below are AS/NZS 1337.1:2010 Tested and approved to AS/NZS 1337.1.2010 for medium impact protection.