I've purchased many not cheap, but not performance, sunglasses over the years and non of them really helped all that much with contrast and shadows. I long ago had a pair of Revo's and loved them. This time I first purchased and returned a pair of Oakley's - terrible for a hundred plus bucks. Bit the bullet and bought these and they are amazing. I actually see better outside with them. My eyes relax behind that lens. I'm very happy. Also very cool, because that's how they make me look. The medium size feels roomy for an average female adult head, but not loose and will not drop or fly off with repeated tries to do so.