How is prayer performed by gesture (imā)? Can one perform prayer by gesturing with the eyes?

In our religion, obligations are determined according to a person's ability, and facilitation is provided for situations beyond one's capacity. Illness is among the reasons for such facilitation. The Prophet (peace be upon him) said, “Pray standing; if you are unable, then pray sitting; if you are unable to do even that, then pray lying on your side.” (Bukhari, Taqsir al-Salat, 19 [1117])

Imā means performing the bowing (ruku‘) and prostration (sujud) in prayer by nodding the head. A person performing prayer by imā bows the head slightly for ruku‘ and bows it a bit more for sujud. It is disliked for someone who cannot place their head on the ground during sujud to prostrate on a raised object placed in front of them. (Sarakhsi, al-Mabsut, 1/217)

According to the Hanafi school, imā must be done with the head. A person who is unable to gesture with the head should postpone the prayer for later (qada); prayer cannot be performed by moving the eyes or eyebrows, nor by intention in the heart. If more than five obligatory prayers pass in this state, it is not necessary to make them up. (Kasani, Bada’i‘, 1/108; Marghinani, al-Hidaya, 1/77)

According to the Shafi‘i school, if a person is unable to gesture with the head, they may perform prayer by moving the eyes or eyebrows; if unable to do even that, then by intention in the heart. It is not necessary to make up prayers performed in this way, but it is recommended (mustahabb) to repeat them if health is regained. (Ramli, Nihayat al-Muhtaj, 1/468-470)

Source: T.C. Diyanet İşleri Başkanlığı, Din İşleri Yüksek Kurulu