How to Spot Fake Polarised Sunglasses
"Polarised" is one of the most abused claims in the sunglasses industry. Many cheap sunglasses labelled as polarised aren't actually polarised at all — or use such low-quality polarisation that it's ineffective. Here's how to spot the fakes.
The LCD Screen Test
This is the simplest and most reliable test:
- Open any LCD screen — your phone, a computer monitor, or a car dashboard display.
- Look at the screen through one lens of the sunglasses.
- Slowly rotate the sunglasses 90 degrees while looking through the lens.
Truly polarised lenses will cause the screen to darken dramatically (often going nearly black) at a 90-degree rotation. This happens because LCD screens emit polarised light, and when the lens polarisation crosses with the screen polarisation, light is blocked.
Fake "polarised" lenses will show no change at any angle — the screen looks the same throughout the rotation.
The Reflection Test
Find a reflective surface — a car bonnet, a puddle, or a glass table — in bright light:
- Look at the reflection with your naked eye. Note the glare.
- Look at the same reflection through the sunglasses.
Truly polarised lenses will dramatically reduce or eliminate the reflection. Fake polarised lenses will simply darken the overall view without selectively removing the glare.
The Two-Lens Test
If you have a pair of sunglasses you know are polarised:
- Hold the known-polarised lens in front of the lens you're testing.
- Rotate one pair 90 degrees relative to the other.
- If both are truly polarised, the overlapping area should go nearly black at 90 degrees.
Label Claims vs Actual Performance
Unfortunately, labelling "polarised" on sunglasses isn't strictly regulated in many markets. Manufacturers can claim polarisation even if the polarising film is so thin or low-quality that it barely functions. Common tricks include:
- Using an extremely thin polarising layer that provides minimal effect
- Labelling as "polarised" when only one lens is treated
- Using "polarised" stickers that peel off to reveal unpolarised lenses
Protecting Yourself
Buy from brands that can back their polarisation claims with specific performance data. Quality polarised lenses block 99%+ of horizontally-polarised light. The ShadyMate Voyager uses premium polarised lenses that you can verify with any of the tests above — because when a product genuinely delivers, testing just confirms it.
