What are polarised sunglasses?

What are polarised sunglasses?

Polarised sunglasses block glare from flat reflective surfaces such as water whilst also providing full UV protection. If strong reflections bother you, polarised sunglasses minimise glare 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 don't provide better UV protection than regular 100% UV lenses. But they do diminish almost all glare, which reduces the strain on your eyes for clearer vision when looking towards harsh reflections.

For driving, water sports or for long durations of sun exposure, polarised sunglasses provide better visual acuity and colour perception for improved visual performance.

But keep in mind, the most important factor for any sunglasses is that they provide 99-100% UV protection to keep your eyes safe from invisible UVA and UVB rays. Non-polarised sunglasses which are UV400 rated are perfectly good for this.

As a secondary benefit to UV protection, polarised sunglasses offer glare reduction for smoother, more consistent vision with less distractions and strain on your eyes.



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

Polarised sunglasses lenses use a filter which blocks glare, whereas non-polarised do not. This filter is called a polariser - a thin film either applied externally or built within the lenses which blocks reflected sunlight (glare) from passing through. This provides a better and more consistent visual experience whilst reducing eye strain.

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.

Polarised lenses are no better or worse for UV protection than non-polarised UV400 lenses.



What are the benefits of polarised sunglasses?

#1 UV protection

Similar to standard UV sun lenses, polarized sunglasses safeguard your eyes from the harmful effects of UV rays. Extended exposure to these rays heightens the risk of developing eye conditions, including cataracts and macular degeneration. Polarized lenses feature a special chemical coating that absorbs UV light, effectively protecting your eyes against potential harm and fostering better eye health.


#2 Glare reduction

The main benefit of polarised sunglasses is reduced glare from surfaces such as water, snow, wet roads and glass. Glare occurs when the sun's rays reflect off these surfaces, creating blindingly strong condensed sunlight that can be hazardous.

By blocking these harsh reflections, polarised lenses allow for clearer vision and reduce the need for your eyes to squint and strain, thereby preventing eye fatigue. This is especially beneficial during activities such as driving, where sudden or prolonged glare can blind drivers, leading to dangerous situations.


#3 Long term comfort

The greatest benefits of polarised sunglasses are felt long term. Compared to regular UV lenses, polarised sunglasses alleviate the compounding effects of eye strain after many hours or even multiple days in the sun.

Repeated exposure to glare adds up over time, which over the course of a week's holiday, driving long distances or fishing all day would otherwise be incredibly taxing on your eyes. This divergence in performance (over time) is where polarised sunglasses are hugely beneficial compared to non-polarised lenses.


#4 Visual clarity

Polarised sunglasses also offer enhanced colour and contrast perception. This improved vision quality makes them ideal for sports and outdoor activities where precision and safety are paramount. Fishermen and boaters, for example, find polarised sunglasses indispensable as they allow for clearer views below the water's surface by eliminating the glare that obstructs the view of fish or underwater hazards.


#5 Aesthetic subtlety

Unlike mirrored sunglasses which are aesthetically very pronounced, polarised lenses are completely undetectable. This makes them look just the same as regular non-polarised sun lenses with a much more traditional, subtle aesthetic.

In case you're wondering, the most common polarised lens colours are grey, brown and green.


Overall polarised sunglasses are a crucial tool for anyone looking to protect their eyes from the sun’s harmful effects while enhancing visual clarity and reducing glare-related strain. Whether for daily use or specific outdoor activities, they provide significant benefits that contribute to both eye health and the quality of visual experience.



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 their in-built polarisers, polarised sunglasses can interfere with LCD screens, darkening digital displays such as your mobile phone, digital car dials, TV screens, camera screens and more. If you heavily rely on 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 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.



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.


Hopefully you found this article helpful. If so, please check out our other polarised sunglasses blog posts for more helpful advice.

Thanks for stopping by.