The Talmud in Sanhedrin 105 interprets “open eye” as referring to the fact that Bilaam was blind in one eye. Targum Onkeles defines “open eye” as meaning that Bilaam had special vision in one eye. How does Onkeles’s explanation coincide with that of the Talmud? The Baal Shem Tov suggests that the two interpretations complement one another. In order to attain the level of nevuah, prophesy, one must be a kadosh, holy person. Kedushah is achieved by purifying each organ of one’s body and sanctifying it. Indeed, this was what the Navi would do.
Bilaam, however, had a problem. He was the antithesis of kedushah. Yet, he attained a remarkable level of prophesy. How did this happen? The Baal Shem Tov explains that Hashem blinded Bilaam in one eye, thereby enabling the kedushah essential for prophesy to enter him through that medium. One organ, the eye, was the only part of Bilaam that he could no longer contaminate. That was the area through which he was able to “see” in order to prophesize. Had he not been “blind” in one eye, he would not have been able to “see” the prophesy of Hashem.
Iturei Torah relates a poignant story that occurred during the Holocaust. A cruel Nazi Gestapo officer, who derived a perverse pleasure from shooting little children, came upon a young woman cradling her baby in her arms. Immediately the bestiality — which was the prominent character trait among his kind — was aroused. The hysterical mother begged and pleaded with him to spare her child. “I see a spark of compassion in your eye. Please spare my child,” cried the mother. The Nazi was shocked at the mother’s claim. “In which eye do you see this spark of compassion?” countered the officer. To his surprise, she pointed to the right eye. The Nazi told her, “You are right, since that eye is not genuine. It is a glass eye that was implanted in Berlin by a master surgeon. How were you able to discern this?” “I saw no evil in that eye,” she responded, “because, as you said, it is not authentic.” The Nazi spared the child.