Tirmidhi

Commentary: 1؎ :
From this hadith it is understood that applying aloe, or any similar substance which does not have fragrance, as a paste to the eyes is permissible;
no expiation (fidyah) will be required for this.
As for substances that do have fragrance, then in cases of necessity and need, it is also permissible to apply them as a paste,
but in such a case, expiation (fidyah) will be required.
The scholars are also in agreement that, in cases of necessity, it is permissible for a muhrim (one in the state of ihram) to apply kohl (surmah) to the eyes, provided it does not contain fragrance;
no expiation (fidyah) will be required for this.
However, Imam Shafi'i and others have considered it disliked (makruh) to apply kohl (surmah) for the purpose of adornment,
and a group has prohibited it.
Imam Ahmad and Ishaq also hold the opinion that applying kohl (surmah) for adornment is not permissible.

“Apply a paste” means to apply a paste of aloe instead of using kohl, because kohl is a colored adornment, and every kind of adornment is prohibited in the state of ihram. By applying a paste of aloe, the discomfort will be alleviated and one will also avoid adornment.

Hadith Commentary: Benefits and Issues: The consensus of the Imams is that for medical treatment, it is permissible for a muhrim (one in the state of ihram) to apply something that does not contain fragrance, and in this case, there is no fidyah (compensatory penalty).
If there is a need to apply something that contains fragrance, then it will be permissible to apply it, but fidyah will become obligatory.
Similarly, applying kohl (surma) to the eyes for adornment—according to Imam Ahmad rahimahullah and Ishaq—is impermissible.
If the fragrance is mild, then charity (sadaqah) is required; if the fragrance is strong, then a sacrificial animal (dam) is required. If one uses fragrant kohl due to illness, then it is necessary to give one of the following as expiation: fasting, charity, or sacrifice.
The same ruling applies to drinking fragrant medicine and using fragrant ointment.

Benefit:
From this hadith, it is understood that during the state of ihram, one may apply an aloe (aloe vera) paste. One should avoid applying kohl (surma), because kohl is a beautification that imparts color, and all forms of beautification are prohibited in ihram. The application of aloe paste will relieve discomfort and also avoid beautification. There is no harm in using medicine, and applying kohl is also permissible; however, it is necessary to ensure that neither the medicine nor the kohl contains any fragrance.