When unpacking the glasses is quite clear, but is indeed a Vario-glasses, so somewhere logical that the coloring occurs only when light falls on it. They are very light, almost unnoticed, this may make you adjust well to the respective head and nose shape. Fogging is nich because the above disc edge slots are available, so that air can circulate also "inside" - really well thought out, while it attracts but not somewhere clean cycling. Then it gets brighter, the glasses colored accordingly, and you have practically more or less always the same brightness in mind - just awesome! The adjustment is therefore very fast vonstatten, especially if you go by the sun in the shade, you can see everything still perfectly good - also a security aspect, for example, even when skiing. Can only hope that they long their services so well done ... Full buy recommendation!
