Light powers are interesting because they can vary so much based on the understanding of the world that they are in. In one system, the effects of the light can be different based on the color of the light, with red being more damaging and fire-based green promoting growth and healing. While color can play a part, there are things that each system needs to consider, and this is how advanced the thought and research were done on light. For example, if the world has done enough, light could be used to see through objects or make lasers.
One of the most common tropes that come with light is the idea that it is a holy power, the pure light being a gift of god and the symbol of good; while this can be easy to do, it can make the character one-dimensional if done incorrectly. But if done well, this feeling of the element can change; for example, a main character could be raised in a church where they worship light, but the main character realizes that just because the person uses light does not mean that they are a good person, this can serve as a call to adventure and have exciting effects on the world.
Light is seen as a healing element in many types of fantasy-based worlds. This can be because there are healing effects of light or because it’s just a large and pure source of energy.