Also what do you think Wakana saw in her first event in the library in Sensei's eyes?(i think tears)
Tears are entirely possible. At first I thought it was just his eyes were shaking out of fear for either remembering more about Sekai or what he might do to Wakana (though in this event Sensei seemed to have control over his actions).
But IIRC Wakana was in fact directly describing his eyes; if it is tear then she should’ve said something like “wait are you about to cry” and got cut off by Sensei in mid sentence, rather than talking about eyes. Same goes for if it is fear in his eyes then she would’ve just described the leaked emotion.
I am also aware that Wakana said you’re uglier than I thought when looking at you this close (I laughed so hard during that). Throughout the game multiple girls seem to describe Sensei’s chaotic eyes as beautiful; his eyes also probably have some kind of charming power, considering how Rin wanting to kiss him after staring into them.
Based on these, I thought his eyes were temporarily back to normal for whatever reason (we saw Sensei once had normal eyes when having a glimpse of Sensei and Niki’s past). But well may god condemn the camera angle that makes us wonder even a tiniest thing.