The most important factors when choosing sunglasses lenses
You’ve chosen your favourite sunglasses, but do they have the right sunglassES lenses for you?
It goes without saying that when choosing sunglasses, aside from their look and fit the most important thing you should focus is the choice of the right sunglasses lenses for protection of your eyes and visibility performance.
As a matter of fact choosing the wrong sunglasses lenses could lead to some serious eye damage and unfortunately the majority of people have absolutely no clue about this subject.
Anyone who spends time outdoors is at risk of eye problems from UV radiation.
Risks of eye damage from UV (Ultraviolet) and HEV (High Energy Visible or Blue Light) exposure change from day to day and depend on a number of elements:
- Geographic location: UV levels are greater in tropical areas near the earth’s equator. The farther you are from the equator, the smaller your risk
- Altitude: UV levels are greater at higher altitudes
- Time of day: UV and HEV levels are greater when the sun is high in the sky, typically from 10 am to 2 pm
- Setting: UV and HEV levels are greater in wide-open spaces, especially when highly reflective surfaces are present, like snow and sand. In fact, UV exposure can nearly double when UV rays are reflected from the snow. UV exposure is less likely in urban settings, where tall buildings shade the streets.
To shield your eyes from UV exposure is fundamental when choosing the right sunglasses lenses for your individual needs.
Although there are multiple factors that characterize sun lenses, the most important of them all is the lens category.
Sunglasses lenses provide varying levels of protection from the harmful effect of the sun and consequently they are ranked by the AS/NZS 1067:2003 Standard (‘the Standard’) in five different categories ranging from 0 (lightest tint) to 4 (darkest tint).
Each category offers increasingly stronger protection depending on the amount of UV rays they allow to penetrate: 0 offering very low protection and 4 offering the highest protection.
Sunglasses lenses: THESE are the five categories
Lens category 0 – Fashion spectacles
These are not sunglasses, as they have a very low ability to reduce sun glare. They provide limited UV protection.
Lens category 1 – Fashion spectacles
Like category 0 lenses, these are not sunglasses; however, they do provide slightly higher (though still limited) sun glare reduction and UV protection than category 0 lenses. Not suitable for driving at night.
Lens category 2 – Sunglasses
These sunglasses provide a medium level of sun glare reduction and good UV protection.
This lens type has a slightly darker tint, which allows less light to be transferred than category 1, but a little more than category 3.
Lens category 3 – Sunglasses
These sunglasses provide a good level of UV protection and a high level of sun glare reduction.
Category 3 lenses allow only 20% of visible light to be transferred, while successfully blocking out the remaining 80% for a higher level of protection, which makes them the prime choice of sun lens for everyday use.
Lens category 4 – Special purpose sunglasses
These are special purpose sunglasses lenses that provide a very high level of sun glare reduction and good UV protection. They are best used for specialised activities in settings that have strong and reflecting sunlight. Not suitable for everyday wearing and must not be used when driving.
As a rule of thumb, if you use your sunglasses to protect yourself from the everyday sun exposure look for sun lens category of at least 2 or preferably 3.
Any lens of category 0 and 1 is purely used as a fashion accessory and no other than that.
At the opposite, go for category 4 lenses only if you are exposed to extreme sun light conditions like high altitude, snow or sea (definitely not for driving).
For the above reasons, all OBLYK sunglasses are made with high quality sun lenses of categories 2 and 3.