...I've been dealing with this for a while, but what causes it, and how do I keep it from happening?

It seems certain eye surface materials show up black until rendered, but considering the comic book settings depend on a render directly from preview this is a serious pain. It seems every other time I load a figure I need to go and manually tweak the eye surface settings in the material room so that they show up as transparent:

Is there some kind of universal setting that I can tick or un-tick that makes transparent eye surfaces actually preview as transparent?

The only way I've found to fix it, is to remove everything from the eyes, delete all the plugins(simply unplugging them isn't enough, they must be deleted), and setting everything but transparency to zero, and transparency to one:

...now deleting everything within the material(note everything is already unplugged and set to zero):

...is this supposed to work this way, is it a bug, how do I get it to work as expected without manually tweaking everything?