If you have a favourite pair of 'specs' Clip Ons are useful to keep with you when you're out and about in bright sunshine or driving as they quickly transform your specs into sunglasses by clipping over the frame. And most of the options here have polarised lenses too.
Converts spectacles to polarised sunglasses
Converts spectacles to polarised sunglasses
Converts spectacles to polarised sunglasses
Converts spectacles to polarised sunglasses
Converts spectacles to polarised sunglasses
Converts spectacles to polarised sunglasses
Converts spectacles to polarised sunglasses
Converts spectacles to polarised sunglasses
Converts spectacles to polarised sunglasses
Converts spectacles to polarised sunglasses