Using a UV light to test eye protection factor of sunglasses

A few months ago I blogged about my shocking discovery that sunglasses expire. Over time, our favourite travel accessory for sunny destinations no longer protects our eyes from UV rays. The UV coating degrades over time.

Upon discovering this I decided that I was going to order a UV light so that I could test my sunglasses, promising a video update after I had tested all of my sunglasses for UV protectant. Some of my sunglasses are over 10 years old, therefore I’m pretty sure they are going to fail the UV light testing.

In my original post, I reference this news article on ABC 7 News which explains how to test your sunglasses for efficacy. This is the method I used to test mine because it’s proven to work. I ordered this UV light from Amazon and made sure it was appropriate for this test.

Woman wearing sunglasses in the park
Me wearing the Prada sunglasses that started this whole saga! If they hadn’t made my eyes burn, I would never have researched sunglasses UV protectant.

As promised, below is the video of me testing my sunnies. I tested several of them on video so you could see how results vary with sunglasses of various ages. Enjoy!

The Instagram link isn’t working on all devices so if you can’t see the video above, visit to check it out.

My Pradas may have passed my at-home UV light test, but I still don’t trust them… And because some of you asked after I posted my IGTV video, I found the dollar store sunglasses I bought in Arizona. The ones I mentioned and were pictured in my original post here. I tested them with the UV light. They passed. While they were a mere $8 US at a dollar store, they did have a sticker stating UV 400 protection, meaning they block out 99% of UV light.

I took my sunglasses on and off a few times over the days I was in Arizona and the only times my eyes hurt was then I was wearing my Prada sunglasses. Therefore, I have to assume they were the culprit. I do love them though so I think I’ll have the lenses replaced. Have your sunglasses ever made your eyes burn? I wanna know if I’m alone in this!