^ I get that sometimes, minus the panic attacks. The visual distortions for me are usually pretty mild-- along the lines of swimming/waving patterns on patterned surfaces, occasional visual static, and noticing patterns in random textures-- which are usually more noticeable if I get tired and start slipping into a depersonalized/derealized state. The DP/DR predates my drug use, and is actually somewhat prevalent on my father's side of the family.
It's been many years since my heavy drug use days, although I will occasionally indulge in a little something or other maybe once ore twice a year. While I don't notice the symptoms as much, they don't seem to be going anywhere in my case. I don't mind much though, since they only ever show up when I'm otherwise stressed (e.g. by being tired, psych stress, etc...) I can use them as a gauge of my psychological state, and perhaps change what I'm doing.