The clip on sunglasses are just what I wanted. They are cut correctly, sized right, and more importantly, are not too dark. Good purchase!
These work well for those of us who need prescription lenses - just pop them over the glasses. They work well because of their simplicity. They are light enough that one barely notices them after a few minutes and they are straightforward, no complications that come along with 'flip ups'. The square'ish' shape will cover almost all shapes of frames underneath. The black color is dense enough that it is difficult for your eyes to be seen from the outside, even in bright sun. A bit less dense might be better (next time). Good value, light & simple, highly recommended.