Choosing sunglasses can be a daunting task, especially if you know very little about them. There’s all sorts of ratings and sizes and different shapes that can be considered before you pick up “the right pair”. Here you’ll find a quick rundown of one of those ratings, referred to as Lens Category.
The lens category on sunglasses indicates the percentage of light that passes through the lenses. These numbers should not be confused with the level of UV protection, which indicates the ability of the lenses to filter the suns more harmful UV rays. Each lens thus has a visible light transmission percentage corresponding to the brightness produced by the sun that the lens lets through.
Remember, 100% of ORAO glasses are 100% anti-UV guaranteed, for all lens categories!
There are a total of 5 lens categories (0 to 4). You should be aware that the higher the category, the less light passes through the lens and the higher the sun glare reduction. Thus, the lens category should be chosen depending on the ultimate use of the sunglasses. It’s important to choose them in accordance with the weather conditions.
This category includes all clear lenses with little or no tint. Sunglasses with Category 0 lenses are designed to be worn for indoor sports, at night or in bad weather (rain, thick cloud). They also serve as protective glasses against dust and wind. They have an anti-reflective coating to reduce annoying reflections and their clear lenses don’t obscure your vision in any way. Category 0 lenses let through between 80 and 100% of visible light.
Category 1 sunglass lenses are designed to be worn in bad weather, in fog and when practising sport in the forest where there is low light. These clear lenses are usually yellow in colour. They improve contrasts and help reduce glare. Category 1 lenses let through between 43 and 80% of visible light.
Ideal for variable weather (alternating between sun and clouds), category 2 sunglasses should be chosen for medium light conditions. Category 2 lenses let through between 14 and 43% of visible light.
This is the most common lens category. Sunglasses with category 3 lenses are designed for sport in bright sunlight. These lenses, usually grey or brown, are suitable for sunny weather at low or medium altitude with strong sunlight. Their tint helps restore natural colour vision. Category 3 lenses let through between 8 and 17% of visible light.
The lenses in this category are very dark and reserved for exceptional and very intense sun brightness: high altitude or in the tropics. Category 4 lenses are ideal for cases in which sunlight is extreme and glare at its highest. The tinted lenses, generally brown, serve to increase contrast. These lenses are very dark and let through between 3 and 8% of visible light.
Do NOT use category 4 lenses while driving. You will not see well and it isn’t safe.
Quick Cheat Sheet
|Summary and Uses|
|Category 0||80 to 100%||Very little tint. Typically designed for indoor sports, night or bad weather (rain, thick cloud). They also serve as protective glasses against dust and wind.|
|Category 1||43 to 80%||Designed for bad weather, fog or practising sport in low light. These clear lenses are usually yellow in colour. They improve contrasts and help reduce glare.|
|Category 2||14 to 43%||
Ideal for variable weather (alternating between sun and clouds). Should be chosen for medium light conditions.
|Category 3||8 to 17%||Most common lens category. Category 3 lenses are designed for sport in bright sunlight. Usually grey or brown, these are suitable for sunny weather at low or medium altitude with strong sunlight. Their tint helps restore natural colour vision.|
|Category 4||3 to 8%||Very dark and reserved for exceptional brightness: high altitude or the tropics. Ideal for extreme sunlight and high glare. The tinted lenses, generally brown, serve to increase contrast.|