The intervention group patients were fitted with an eye mask designed by the researcher by placing a black fabric in the size of the mask between two three-layer surgical masks with Asfor brand soft elastic earphones and stapling the edges. The designed eye mask was cut with scissors according to the shape of the nose so that the mask would fit the eye exactly and prevent the light from entering the eye. A separate mask was used for each patient in the intervention group. Patients who were admitted to the SICU after surgery were evaluated for agitation-pain-delirium at 23:00 on postoperative days 0, 1, and 2, were told to wear their eye masks after the scale application, and the patients were allowed to sleep at 23:00 at the latest. Patients were allowed to remove the eye patch for short periods of time (10 minutes or less at a time) and then put it back on when uncomfortable and when necessary.

Control group received the usual care.

The intervention group patients were fitted with an eye mask designed by the researcher by placing a black fabric in the size of the mask between two three-layer surgical masks with Asfor brand soft elastic earphones and stapling the edges. The designed eye mask was cut with scissors according to the shape of the nose so that the mask would fit the eye exactly and prevent the light from entering the eye. A separate mask was used for each patient in the intervention group. Patients who were admitted to the NICU after surgery were evaluated for agitation-pain-delirium at 23:00 on postoperative days 0, 1, and 2, were told to wear their eye masks after the scale application, and the patients were allowed to sleep at 23:00 at the latest. Patients were allowed to remove the eye patch for short periods of time (10 minutes or less at a time) and then put it back on when uncomfortable and when necessary.

This form was developed by the researcher using the literature on the subject. The form was filled in based on the self-report of the patients. In order to determine the sleep status of the patients, the form included 5 statements: 'I feel tired and sleepy during the day despite sleeping for a sufficient amount of time', 'I have difficulty falling asleep 2-3 nights a week', 'I have to constantly move my legs in bed', 'I have to go to the toilet at least once during the night', 'I wake up tired and with a headache in the morning'.

It is a ten-level scale developed by Cook and Palma (1989) in which eye contact, which is not present in other scales, is evaluated following the verbal stimulus. In the scale, a score of '0' indicates the ideal level where the patient is awake and calm, while values up to '+4' reflect increasing agitation and values up to '-5' reflect increasing sedation level. As the scale score increases, it is interpreted as the agitation status of the patients worsens.

Richard-Campbell Sleep Scale (RCS): In 1987, the Turkish validity and reliability study of the scale was conducted by Richards in 2015 by Özlü and Özer. The scale consists of 6 items evaluating sleep quality, depth of sleep at night, frequency of awakening, ambient sound level, time of staying awake and time to fall asleep. Each item is evaluated on a scale ranging from 0 to 100. A score between '0-25' indicates very poor sleep and a score between '76-100' indicates very good sleep. As the scale score increases, patients' It is interpreted that sleep quality has increased.