What are polarised sunglasses?

Polarised sun lenses block glare from flat reflective surfaces such as water or glass. If strong reflections bother you, polarised sunglasses minimise this effect for improved visual clarity, definition and colour perception.

 

To understand how polarised sunglasses work, this guide explains the effects of glare and how these premium lenses help to improve your vision.

 

 

What is the benefit of Polarised sunglasses?

Primarily, polarised sunglasses are better at blocking glare than regular sun lenses. This benefit reduces visual strain over long durations in the sun. Furthermore, polarised lenses offer superior colour contrast and visual acuity, all whilst providing crucial UV protection.

 

Are polarised lenses worth it?

If you spend a lot of time outside, near water, driving or in outdoor activities, polarised lenses are worth your investment. By blocking glare, they reduce the strain on your eyes which would otherwise leave your eyes feeling frazzled after your day in the sun.

Polarised lenses cost approximately 30% more than non-polarised equivalents, but offer superior optical performance.

 

Which is better UV or polarised sunglasses?

Polarised or not, all sunglasses must block at least 99% of UV light. Polarised sunglasses are still UV protective, but have the secondary benefit of blocking glare.

On sunglasses, look for the UV40 or UV400 marking. This means the lenses are certified to protect your eyes from UV light in accordance with international and European law.

This certification provides you with the recognisable and necessary protection from the damaging effects of ultraviolet light which would otherwise damage your eyes.

 

Are polarised sunglasses better?

Polarised sunglasses are better if you rely on good visual performance when driving, near water or for long durations of sun exposure. Compared to non-polarised sunglasses, they provide superior visual acuity in varying sunlight, helping to block glare.

 

Polarised sunlight hitting car windscreen

 

Are polarised sunglasses good for driving?

By blocking glare, polarised lenses reduce visual fatigue on long car journeys. This is helpful on bright days when sunlight is continuously taxing your eyes whilst you focus on driving.

 

 

"Polarised sunglasses can be helpful for driving, too, because they reduce glare-causing reflections from flat surfaces, such as the hood of the car or the road's surface”.

Erinn Morgan: Allaboutvision.com

 

However, your polarised lenses may interfere with your ability to see your dashboard controls or when filling your car with fuel. Notoriously, polarised lenses are known to dim LCD screens which can make them difficult to read.

For more advice on polarised sunglasses for driving, check out our handy blog article.

Polarised sunglasses for driving

 

Illustration showing how polarised lenses block glare

"How polarised lenses work" | © Banton Frameworks Ltd | For image sharing enquiries, please contact us.

 

How do polarised lenses work?

Polarised lenses work by blocking horizontally orientated light (glare) from entering the lens. This is how they improve colour perception and contrast through your lenses, whilst reducing eye strain.

For more detail, it helps to know how sunlight behaves.

When light reflects off flat shiny surfaces such as water, it becomes condensed and horizontally orientated into glare. This makes is very difficult to see, even through regular sun lenses.

To reduce glare, polarised lenses contain a chemical film called a polariser which is sandwiched within the layers of the lens construction. Upon the polariser are hundreds of chemically aligned molecules in neat vertical rows.

These rows create a filter of vertical slots through which only vertically orientated visble light can pass. This prevents any horizontal light from entering through your sunglasses to drastically reduce glare.

 

Greyscale portrait of bearded man with long hair wearing sunglasses

 

Do polarised lenses protect your eyes?

When buying polarised sunglasses, check they’re labelled with a UV40 or UV400 marking to ensure they’ve sufficient ultraviolet protection. Illegitimate sun lenses expose your eyes to invisible UV light which can lead to long term damage.

Ironically, dark tinted lenses dilate your pupils to let more light in. Without UV protection, black market sunglasses are actually worse than wearing no sunglasses at all!

 

At Banton Frameworks, our handmade sunglasses are fitted with polarised lenses which are 100% UV protective.

 

 

“UVA and UVB rays can harm our skin and our eyes. The damage to our eyes can include sunburn of the cornea (sometimes called snow blindness), skin aging, macular degeneration, cataracts and skin cancer, so proper protection for our eyes is vital.”

"Trust me, I'm a Doctor" BBC

 

 

Side view of bearded man on sail yacht wearing polarised sunglasses and white shirt

 

What is the use of polarised sunglasses?

Polarised lenses are used to reduce the distortion and visual fatigue caused by glare. This makes them popular for driving or water sports such as fishing or sailing.

Reflected sunlight from water or a shiny car bonnet or wet road would otherwise make it difficult to see properly. Polarised sunglasses vastly minimise this glare to improve your ability to detect oncoming potential hazards.

Popular uses of polarised sunglasses include;

  • Sailing
  • Skiing
  • Driving
  • Mountaineering
  • Fishing

 

Looking at an LCD phone screen with polarised sunglasses

 

What are the pros and cons of polarised sunglasses?

The main pro of polarised sunglasses is their ability to block glare. However, they’re more costly than non-polarised equivalents and effect how you see digital screens.

For their extra performance, polarised come at a slightly higher cost. According to our market research they cost an average of 30% more than regular, non-polarised equivalents.

Polarised lenses also have a habit of darkening liquid crystal displays (LCD’s) on digital devices such as phones, bank machines, computers or tablets.

This due to the angle of the light that’s emitted from these devices which can be partially or entirely blocked by the polariser film in polarised lenses. Using your phone or reading a bank machine screen can be hindered by polarised sunglasses.

To remedy this issue, you may want to remove or look over/under the lens to see properly which can be annoying to get used to.

 

 

How can you tell if sunglasses are polarised?

Regular sun lenses look identical to polarised ones. If you want to check your lenses are definitely polarised, here’s a handy method you can use to make sure they’re legit.

 

  1. Grab your mobile phone.
  2. Hold your sunglasses in front of the screen
  3. Look through one lens and slowly rotate the frame
  4. Check if the light changes in brightness
  5. If the light changes, they’re polarised

 

Summary

Polarised sunglasses are great for improving your overall visual definition.

They're slightly more expensive than regular, non-polarised sunglasses but they can block nearly all reflected glare from affecting your vision. For activities such as driving or for sport, the reduction of glare can really help to reduce eye strain over long periods of focus.

Remember that polarised sunglasses can have a dimming effect on LCD screens which can block information from digital displays.

Thanks for stopping by.

 

BFW x JAPAN: WIRE-SLV 310

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