Q. Can eye drops be used in Shabbos after a cataracts operation?
A. Our Sages teach (Avodah Zarah 28b): “A man’s eyes are connected to his heart.” Thus, if we see that one’s eye is in danger, it is equivalent to an ailment in the person’s heart and one can desecrate Shabbos in order to prevent his death. Therefore, Shulchan Aruch (O.H. 328: 9) rules that when one’s eye is so irritated that it emanates blood, purulence or constant tears from pain, one can desecrate Shabbos to cure it. Mishna Berura (ibid. 22) explains that it is tantamount to life danger.
Poskim write that if one experiences a sharp and strong eye inflammation, sharp eye pains, an eye injury, or a severe loss of vision, Shabbos should be desecrated, even if these symptoms occur only in one eye. (Eglei Tal – Tochen 17, Shemiras Shabbos K. 34: 8, Halichos Shlomo, Ohr Letzion 2: 47: 27, et. al.).
Horav Shlomo Miller’s Shlit’a opinion is that eye drops are permitted after an eye operation such as cataracts.
Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit’a