In Night, how does Wiesel use his eyes to see someone's willingness to live?

One example of how Eliezer uses his eyes to see someone's willingness to live can be seen in his perceptions of Moshe the Beadle.

Moshe the Beadle was Eliezer's spiritual teacher.  Eliezer learned about spiritual notions of the good from him. Eliezer is "deeply observant" when it comes to his teacher. He would use his eyes to observe his master pray, lecture, and thoughtfully answer Eliezer's questions. Eliezer's power of observation extended to the way...

One example of how Eliezer uses his eyes to see someone's willingness to live can be seen in his perceptions of Moshe the Beadle.

Moshe the Beadle was Eliezer's spiritual teacher.  Eliezer learned about spiritual notions of the good from him. Eliezer is "deeply observant" when it comes to his teacher. He would use his eyes to observe his master pray, lecture, and thoughtfully answer Eliezer's questions. Eliezer's power of observation extended to the way he describes Moshe's "wide, dreamy, eyes" which were always "gazing off into the distance."  

From this observant demeanor, Eliezer is able to see Moshe the Beadle's desire to live.  This willingness is evident in how he wants to save the townspeople from the Nazis.  Eliezer sees how Moshe the Beadle pleads with the people from Sighet as well as the pain he experiences when his actions prove to be futile.  Eliezer observes the hope turning into sadness when he describes the tears that flowed from Moshe's eyes "like drops of wax."  Eliezer can see Moshe's hurt in the master's words:

"You don't understand,' he said in despair. 'You cannot understand. I was saved miraculously. I succeeded in coming back. Where did I get my strength? I wanted to return to Sighet to describe to you my death so that you might ready yourselves while there is still time. Life? I no longer care to live. I am alone. But I wanted to come back to warn you. Only no one is listening to me."

Eliezer's eyes captures Moshe's willingness to live.  It is a desire that motivates Moshe the Beadle to warn others about what lies ahead.  Eliezer's observant eyes are the means through which he understands the intensity of the desire to live.