Sunglasses for running

[DeepfriedPizza]

Can anyone point me in the direction of cheap sunglasses for running?
I have quite sensitive eyes so even when it doesn't seem blazingly sunny I seem to find it too bright.

I wanted to try in in a shop so have tried sports direct, TK Maxx, an independant sport shop and JD sports.

Any other suggestions? I don't want to spend more than £20

I've got some like this that I use for running, although fairly often I end up in my normal
Raybans. The wiggle ones are good and very comfortable though.

www.wiggle.co.uk/dhb-ultralite-sunglasses/