I purchased Ocean Eyeware Photochromic sunglasses. The photochrome disappeared after only 5 months leaving me with pale brown lenses that don't change at all. I contacted Ocean Eyeware and was told this happens, buy some more from our online store??? They told me the lifespan was approx 2 years but mine lasted less than 25% of the stated time. Where does it state the effectiveness expires when you purchase the glasses, I've never heard of it. Needless to say, unless they come to the party I will never touch their product again.