List of Onsen benefit which body parts?

which onsen is good for the eyes? and throat?

Nuruyu Onsen in Fukushima prefecture
Kaikake Onsen in Niigata prefecture
Ubako Onsen in Kanagawa Prefecture

Those three seem to be best known for their benefits to the eyes, though people go there repeatedly, not just once :)

For the throat, Misasa Onsen in Tottori prefecture seems to have some steam bath facility that is said to be good for the throat.

As said, onsen soaking is not a miracle cure for just one time experience. Also many claim good for this and that but nothing scientifically/medically proven anyway. So just feel good soaking in any onsen bath. I only go to those onsen with once through hot water flow(maybe mixed with cold water to cool down). Many where don't have enough hot spring water flow or have pumped lukewarm water from deep well have recirculated and reheated water.

Take a vacation from your worries and stress of thinking about your illness. That is what any onsen is good for.

Thanks so much for the kind answers.