Nexts own brand of designer glasses start from £20 including a sun lens and then theres also a massive choice of designer sunglasses to choose from too. Bit dearer but all have just a £5 sun lens to be added.
The banner on their site just brings up the sunglasses but click the NEXT BRANDED on the mens and womens glasses dropdowns and you can add them to these cheaper ones too !!
Hope this helps someone with all the nice weather we're having ! :