Lens quality

The quality of opical polycarbonate and glass lenses for distortion free, such as the waves and the blemishes, to see evenly the distributed colour of each lense across. You can tell when the lenses in a pair of sunglasses are a good quality, to find out for yourself, you need to find the on the surface of the lense an repeating lines. With your glasses hold them a short disance away for your face and have one eye closed, then look at the line!! on the lense and move up and down, aswell left to right slowly, when you are doing this they should stay straight when your looking, if you do not see the line straight and it is a little wave or even wiggle then the lenses are not optical quality and this will distort your eye vision, with cheaper eyewear glasses it is an commom thing to happen for the distortion on the lenses.