When you picked out your latest pair of shades, did you primarily pick them out based upon looks or health? If you are like me, you probably bought them based on the way they looked on your face.
UV radiation from the sun cannot only damage your skin, but also your eyes, specifically the conjunctiva and cornea, leading to many problems, including cataracts.
When you choose your next pair of sunglasses, look for UV protection details that block at least 99% of UVB rays and 95% of UVA rays (American National Standards Institute).
Do you think since your glasses are "polarized" they are better at protecting the sun? Not necessarily. There are many polarized glasses (to help block the glare from the sun) that do not always protect against UV rays.
If you are having a hard time finding sunglasses that not only are stylish, but also block the harmful rays, you can always have your glasses treated with a material that provides UV protection.
Good luck with your next purchase and stay healthy!