[Scales]

I had a clownfish go blind years ago. My research then (before I "discovered" the internet) suggested that nutritional deficiencies were to blame...but who knows??? The fish lost a lot of weight initially but I eventually taught him to eat from my hand (I assume you are not crazy enough to try hand feeding your lionfish). His desire for food resulted in him hanging out in the top fornt right corner of my tank, where it was easy to feed him...he actually became quite fat. He did not respond to any movement or attempts to startle him. He lived for about two years in his blind condition...and then died after a carpet surfing incident.