For those of us who wear the ol' goggles, GD has a nice offer with MSE for two pairs of glasses with free Sunglasses tints for £22 (non-special lenses and a specific range only), just bagged myself some as I had my eyes looked at yesterday so have a fresh prescription... 
http://www.moneysavingexpert.com/deals/glasses-direct#deal35491
Just paid my £22 for two pairs that should have been £120 total, it's great being a cheapskate... 