In reply to your letter of
Rosh Chodesh Kislev, in which you write that the doctor is advising you to have surgery on your eye:
I surely need not make you aware that you should be scrupulous in the observance of Kiddush and Havdalah, as this has an impact on the "luminary of the eyes of man."
So, too, with regard to an increased effort in matters relating to honoring the Torah and those who study it — in keeping with the verse, "For a mitzvah is a candle, and Torah is light."
As G-d recompenses "measure for measure," this [scrupulous] conduct will serve to strengthen and enhance your vision, the "luminary" of your eyes.
Establish regular Torah study sessions in the exoteric portion of Torah and in the esoteric Toras HaChassidus, doing so in a broad and ample manner and in good health.
With blessings for a speedy recovery.
(Igros Kodesh, Vol. VII, p. 80)
I received your letter, and at an auspicious time I will pray for your good health at the sacred resting place of my father-in-law, the Rebbe, of blessed memory.
In all probability, you hear Kiddush and Havdalah and also taste of the Kiddush wine. [Conduct yourself as well] in accordance with the Jewish custom of dipping the finger in the remains of the Havdalah wine and touching the eyes — understandably, the outside of the eyes, [i.e., the eyelids,] which as stated in Sefarim is a segulah for the "'luminary' eyes of man."
May G-d see to it that your actions meet with success.
(Igros Kodesh, Vol. XII, p. 225)
In reply to your letter in which you describe your health status, particularly with regard to your eye:
Surely you will continue to follow your doctors' instructions, and may G-d send His healing words and heal you.
I surely need not remind you of the saying of our Sages, of blessed memory, that scrupulous observance of Kiddush and Havdalah have a particularly beneficial effect on the "luminary of the eyes of man."
In addition to the above, you should increase your amount of Chassidus study on Shabbos. ...
(Igros Kodesh, Vol. VIII, p. 304)
... Concerning your notification to me that the doctors decided to operate on Mrs. ...
tichye's one eye without much delay, may it be G-d's will that the operation be successful and that she soon return to unfailing good health.
I am not familiar with the custom there, but if there is an "eternal flame" (a ner tamid) in the shul, she should participate in its upkeep (but she should not pay for placing one there if there is none). If there is none there, then she should undertake for a period of time to pay for the lighting costs of the shul.
Surely she lights candles erev Shabbos and Yom Tov. It would be beneficial for her to give some tzedakah to the charity of R. Meir Baal HaNes prior to candle lighting. ...
(Igros Kodesh, Vol. V, p. 161)