I haven't found a whole lot of info on glowing red eyes. I have heard that dragonscales will often go blind as they get older because their scales will grow over their eyes.
And I also was careful acclimating him. It took me at least two hours to do so. But I would think that shock would be more sudden? It definitely wasn't sudden.
I just checked on him and he was in his cave resting his tail on the gravel in a strange position. o_o Maybe he was sleeping? I figure he would sleep even with the lights on, lol. Before he went blind I had no idea where he slept because even if it was pitch dark he saw me coming, haha.