Cubozoa are ripe for study if you're curious about primitive vision and its applications. They are notoriously venomous, so handle with care, but if we can trust undergrads with caring for them in the lab I trust the average tinkerer can work out how to not get stung. This guy seems like he's got the right stuff.
Our world is such an amazing place — just full of things we barely notice but are a lifetime of fascination if you just dive into them, as this guy is doing.