If you can't see anything, it's likely you're outside on a very dark night. Sometimes there's a moon or you're in an area with street lighting, but sometimes there just isn't enough light to see.
If you're somewhere familiar you can try to get inside or into a lighter area by using memory or a map. However, if you're completely lost you may need to use the 'godmother' command to get back to safety.
You can avoid getting into this situation by carrying a light source with you. For example, there are lightable torches, which are cheap but heavy and don't last long, or there is a yellow stone ring which uses guild points (see help gp) but never runs out, or there are a number of other ways of lighting your way.
mellandrin, little_miss_kaea |