AVOS 2.13 AVOS 2.9
עין טובה - ayin tovah - R Yonah explains to mean נדיבות - generosity. This is a huge chiddush - that generosity is not seated in the heart but rather in the EYES!
We tend to understand that our eyes are receptive organs, receiving and absorbing the sights we see. It is this general error that causes such difficulty with the challenges of לא תתורו - if our eyes act as scouts for the body we are already in trouble. From this R Yonah we see that eyes can GIVING! Instead of always being used for זנות - which means to nourish and feed, they can be tools to provide and give!
R' Chaim Shmuelevitz and R' Nosson Tzvi Finkel both point out the interesting distinction between one who deafens another, in which case he pays the full monetary value of the victim, and when one blinds another in which case the person's value is not fully diminished. And yet only a blind man is considered like dead, but a deaf man is still considered alive! Although from a monetary point of view a deaf person is not financially productive, so long as he can see, he can still give to others with his eyes - and that is life!
Every trait and character in the nefesh has a physical limb with which it uses as its instrument. R Yeruchom writes that the ability to accept and absorb a lesson is rooted in the physical tool of our ears. Hence we drill the ear of a slave and not his heart or brain. We see from R' Yonah that the instrument of נדיבות - a generous spirit - is in the body's EYES.
When Moshe Rabeinu first went out to his brothers it says וירא בסבלותם he looked at their burden - to which Rashi explains נתן עינו וליבו - He GAVE his eyes and hearts.
We can look at people and exude warmth, acceptance, love, respect. We can express and share happiness with others or express pain and share in someone's burden. The eyes are not just passive receptors like the ears, they can be actively generous. An ayin tovah is a generous EYE.