Direct sunlight is always scattered, with the blue portion of light being subject to the greatest scatter. Our colour perception is influenced by this effect, as all colours contain a small portion of blue. This is why, for instance, we see the sky as blue.
Due to the blue portion, all chromatic zones are shifted towards blue. The closer the coordinates are to each other, the less contrast is seen. The result is glare and blurred outlines which are particularly annoying in extreme light conditions, e. g. in dazzling sunshine on water or in diffuse light on the ski-run.