It was 5752 (late 1991). The Rebbe was hunched over his volume of Gemara, deep in thought, when he noticed a blurriness in the Aramaic script. He rubbed his eyes, but the smaller letters on the page did not get clearer.
He summoned me (Rabbi Leibel Groner) with the complaint, and I promptly phoned an eye doctor. This man, a prominent ophthalmologist and well-traveled communal figure, came to the Rebbe’s office in 770 and gave a private examination.
He looked over the Rebbe’s glasses, as well, and increased the prescription. None of this worked, and again the Rebbe summoned me. So I again phoned the doctor.
“This might require a more intensive exam,” the doctor said, after listening to me. “I have an instrument at the office I can use, but it isn’t portable. I’m afraid the Rebbe will have to come over here.” Knowing of the Rebbe’s need for privacy, he added, “I can arrange a time when no one else is around.”
So the Rebbe went. Opening wide the Rebbe’s eyes, the doctor deftly squeezed into them the liquid from the dropper. “It will take about fifteen minutes for dilation to take effect,” the doctor said.
Taking advantage of the interval, he decided to ask the Rebbe a question. “As the Rebbe knows, I have visited many places in the world and seen many things, wonderful but also tragic. How is it that with all Chabad has accomplished, Moshiach still hasn’t come?”
The Rebbe smiled broadly. “I have the same question, but apparently there’s a little left to do to fill the cup.” To make his point, he motioned with his hand. “This is why,” he continued, “that whenever I speak to the Chassidim, I urge them to do a bit more. I don’t let my Chassidim sleep.”
Told by Rabbi Leibel Groner. Source: COLlive and the Avner Institute