While the human body is a pretty remarkable and complex thing, it relies on its senses to react to its surroundings. If it’s dark out, you’d best believe it would be difficult to walk sufficiently, as you have no clue how close or far away things are because you can’t go off of visual depth perception.
In these cases, having something like the SpotLit LED around could be rather useful. It can attach to your keyring or zipper, and will give you the light you need to respond to whatever situation you may face. Need to fight a bear at night? It would be much easier if you could see it (not saying you’ll win, but the chances will have gone up slightly). This is weather resistant push-button switch light that can glow or flash for 20-25 hours, and comes in a variety of colors. It’ll cost you around $7.50 for one of these, and it comes on a carabiner clip.