Ultraviolet rays from the sun are incredibly damaging to our eyes, so proper eye protection is important at any time of year. However, choosing the right sunglasses (tinted sunglasses or polarised) is no easy task with so many choices available.
Polarised sunglasses are specialised eyewear designed to reduce glare from surfaces such as water, snow and glass.
First, we need to know what glare is. Glare is difficulty seeing in the presence of bright light such as direct or reflected sunlight. It can generally be divided into two types, discomfort and disability glare. Discomfort glare is an instinctive desire to look away from a bright light source.
Disability glare impairs the vision of objects without necessarily causing discomfort. This could arise for instance when driving westward at sunset.
How do polarised lenses work?
Sunlight can be absorbed or reflected in several different directions. Sunlight that bounces off horizontal surfaces, such as water and land, is usually reflected back in a similar horizontal direction. This causes not only visual discomfort but can also cause a potentially blinding glare.
Polarised lenses contain a laminated filter that allows only vertically oriented light to pass through.
The most common colours of polarised lenses are grey and brown. However, depending on the manufacturer, other colours may be available.
Glare has the potential to create very dangerous situations, especially when driving. Sunlight that is bouncing off horizontal surfaces, i.e. the road, can be vastly reduced with the use of polarised sunglasses.
- Increased visual comfort. Since your eyes are not constantly challenged by glare, it is easier to view objects in bright conditions.
- Enhanced clarity of vision & contrast for ground-level objects & for seeing into the water.
- Reduced eyestrain. Frequent adjustments to glare from reflections are taxing on the eyes and can lead to fatigue.
- Conveys colours faithfully.
- Diminishes reflections and glare.
- Polarised lenses make it difficult to view LCD screens. They create the effect of making images on the screen disappear at certain angles.
- Though recommended for skiing, they may compromise contrast in certain light conditions.
- Sunglasses are generally more expensive than regular tinted lenses. This additional investment is worth it for the majority of people who want to optimise visual comfort.
So, in conclusion, although we have talked a great deal about polarised lenses, to ensure we have a good understanding of what that is we can, therefore, make an informed decision of which root to take. Most tinted sunglasses do have the UVA/UVB protection in the lenses that are required to meet British standards but they don’t provide the same quality of visual comfort we get from polarising. If in any doubt at all ask your optometrist what they wear.