As the days slowly get shorter, it's worth considering that statistics prove flying after dark increases risk. While hazy, marginal weather may still provide a visible horizon during daylight hours, after dark, distinguishing the blend between sky and landscape becomes even more difficult. Even on a clear night, ground lighting can blend dangerously with starlight to confuse the eye. And another element that I rarely hear mentioned: locating switches, dials and other controls in a dark cockpit is that much more difficult, requires that much more attention and robs that much more concentration from intuitively flying the airplane by outside reference. Just when you can afford it least, you might be required to expend significantly more mental energy on cockpit tasks that are usually accomplished with just a glance.