I'm worried because my under-eyes look sunken, making me look older.

I didn't have much flesh under my eyes to begin with, but as I get older, the more I look in the mirror, the more sunken they appear. It makes my complexion look unhealthy and tired, so it's bothering me. When I went to a dermatology clinic for another procedure in the past, they suggested I try under-eye fillers, but since that clinic was run like a factory, I just said yes and didn't get the injections. Is it okay to get fillers for sunken under-eyes? Or are there other procedures available?