Yeah, another rather mundane item using Continual Light.
On a normal arrow or bolt inset a small piece of quartz with Continual Light cast on it near the fletching; then place a loose metal ring that fits well around the shaft of the missile over the quartz to block the light.
When needed, fire the arrow. The fletching keeps the metal ring from slipping back when fired. On impact the metal ring slips forward, exposing the quartz and suddenly flooding the target area with light. In addition to providing illumination to distant areas light arrows can startle enemies, perhaps causing them to flee, or mark a target so that they are easier to follow, such as a wild animal.