Directly, I don't think there is much that light can do other than to blind a creature. Whilst I suppose that constitutes damage, I don't think it would be enough to directly hurt either a predator or prey. Blinding another creature would then leave it very vulnerable to attacking with teeth/claws in order to finish it off.

But it would require a lot of energy to produce such a significant amount of light, so I'm not sure whether it would be useful or not, in terms of the creature surviving or eating the blinded creature to restore the energy used for the light show.

It could always be indirectly damaged however. As indicated in the question [here][1] the light sources could be used in a way that would frighten predators/prey, putting them into a state of submission.

Extending tentacles or antennae with lights on the end and flaring them up in the darkness would make the creature appear to be bigger than it actually is, achieving this effect.

Once the animal that has been attacked is in a frightened state, it would likely be much easier to escape or attack them as they are disoriented.

An animal creating light could always make it flash very quickly in order to induce seizures or hypnosis in other animals, making them even more vulnerable to attack (like how a [stoat dances to hypnotize a rabbit][2] before it attacks) but it would need a very specific predator or prey to succumb to it.


  [1]: https://worldbuilding.stackexchange.com/questions/14861/could-an-animal-species-evolve-to-use-electricity
  [2]: http://video.nationalgeographic.com/video/worlds-deadliest-ngs/deadliest-stoat