What are polarised sunglasses?

Polarised sunglasses are fitted with lenses that block glare from flat reflective surfaces such as water - as well as provide UV protection. If strong reflections bother you, polarised sunglasses minimise this effect for improved visual clarity, definition and colour perception.

 

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

 

Are polarised sunglasses better?

Polarised sunglasses are a better option if you require good visual performance. For tasks such as driving, sports near water or for long durations of sun exposure, they provide superior visual acuity, helping to block glare.

Non-polarised UV sunglasses are still a good option. However, polarised sunglasses offer the same level of safety - with the added bonus of glare reduction. In short, they give you a better overall visual experience with less distractions or strain on your eyes.

 

What's the difference between Polarised and non-polarised sunglasses?

Polarised lenses use a filter which blocks glare, whereas non-polarised do not. This filter is called a polariser - a thin film which is either applied externally or built within the lenses. The polariser is what prevents concentrated sunlight (glare) from interfering with your vision, creating smooth and consistent performance in varying sunlight.

Thanks to this filter, polarised lenses are better at diminishing strongly concentrated sunlight which has been condensed and reflected from flat shiny surfaces such as water or snow. This is they’re main difference to non-polarised lenses and is purely beneficial for visual comfort as opposed to UV protection.

 

Which is better UV or polarised sunglasses?

UV protection is primarily crucial for protecting your eyes against the sun’s damaging and invisible UVA and UVB rays. Polarisation doesn’t provide any UV protection and is simply an aid for improving visual comfort by reducing the severity of glare reflected from water, snow or surrounding surfaces. In short; UV protection is crucial. Polarisation is a bonus.

 

“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

 

 

Does 100% UV mean polarised?

No, 100% UV protection doesn’t mean that sunglasses are polarised. UV400 or UV40 means the lenses can protect your eyes from the damaging frequencies of ultraviolet light, ranging between 10 and 400 nano metres. Polarisation has nothing to do with UV protectivity and is simply an additional filter applied to sunglasses which helps to reduce reflected glare.

 

How do you tell if glasses are polarised?

Polarised sun lenses look identical to regular, non-polarised ones. To check that 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

 

If you’re in a shop, another polarised sunglasses test is to overlap two polarised sunglasses frames. By rotating one of the frames, you’ll block all the light through the overlapping lenses if they are polarised.

This effect happens because the polarisers are at 90 degrees to one another. Little to no light will be able to pass through both polarisers.

 

When should you not wear polarised sunglasses?

Due to the way they work, polarised sunglasses can interfere with LCD screens. They have a habit of darkening digital displays such as your mobile phone, digital car dials, TV screens, camera screens and more. If you need to monitor or be able to use a digital screen whilst wearing your sunglasses, polarised lenses might not be the best option for you.

 

Polarised sunlight hitting car windscreen

Do I need polarised sunglasses for driving?

Polarised sunglasses can be a great option for reducing visual fatigue on long car journeys. On bright sunny days, sunlight unknowingly puts strain on your eyes during long periods of visual focus. By reducing glare from wet roads, other cars or nearby terrain, polarised sunglasses reduce the taxing effects of reflected sunlight on your eyes.

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 this handy blog article.

 

"Polarised sunglasses can be helpful for driving, 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

 

 

Is polarised worth the extra money?

Polarised lenses are a worthy investment if you spend a lot of time outdoors, near water, fishing, sailing, skiing, or driving. 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.

 

What are the disadvantages of polarised sunglasses?

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. This also leaves your eyes exposed to UV light each time you remove your sunglasses.

 

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.

 

 

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