I have a question about iridescent sharks! I've been thinking about purchasing one. Why does it seem that most, if not all, adult iridescent sharks have clouded eyes? It almost looks like they have cataracts. Are these really cataracts? Is there any to prevent the eyes from turning from clear and transparent to being white and filmy? Also, it seems like they go from being pretty and bluish iridescent to dark and dull. Is that natural in the maturation process? Or is that a result of poor care/ stress?? Any info from an experienced keeper would be appreciated!!!!