my sight What I saw

Today I saw an old man standing stood near by me in the bus. I cannot bear this thing [Cannot say this.  He's a human being not a thing.  If you write this, it means you are sneering at him] to see him being happened so I stood up and made the man seated like this.  So I gave up my seat to him. Tired as I was, .I felt satisfied. .I thought I it was great gesture even though it was a little thing act on my part.__As a student someone being young and able, I must take this as my civic duty responsibility.Its my duty to do it.

Good for you.  We all will grow old.

my sight 

Today i saw an old man standing near by me. I cannot could not bear this thing being happened situation, so I stood up and made the man seated sit down.Tired as I was, (add a comma here) I felt satisfied. I thought I it was great even if it was a little thing. As a student I must take this responsibility. Its my duty to do it.

Could you help me understand better what you mean when you say "As a student I must take this responsibility. Its my duty to do it." 

Also what do you mean to say as your title "My Sight?" Could you explain it better?

Wonderful writing and I'm sure the man thanks you in his heart for your kindness.