Introduction. Sight is one of the most important and vital human senses. Lack of proper eye care (EC) in anesthetized patients can lead to serious ocular complications and even vision loss. Insufficient knowledge, attitude, and skills of nurses are considered as a barrier to providing EC in the intensive care unit (ICU). The aim of the present study was to determine the effect of training EC clinical practice guidelines for ICU patients on nurses’ knowledge, attitude, and practice of EC. Methods. This was an interventional study with a pre-post design performed on 60 ICU nurses. For the experimental group, EC clinical guideline training was performed for anesthetized patients in three sessions. The data collection tool included nurses’ clinical competence of the EC questionnaire with a possible score range of 0–86. This tool consists of three domains, including knowledge (0–18), attitude (0–28), and practice (0–40), which was completed in a self-assessment manner before and three months after the training program. Data analysis was carried out using SPSS16. Findings. The mean scores of knowledge, attitude, and practice after the intervention in the experimental and control groups were 15.03 ± 2.72 and 11.11 ± 3.50, 25.65 ± 3.47 and 22.07 ± 3.08, and 33.88 ± 4.14 and 28.5 ± 55.08, respectively, which were statistically significant (
P
≤
0.001
). Also, the total score of clinical competence of EC after the intervention in the experimental and control groups was 74.56 ± 7.93 and 61.74 ± 9.66, which showed a significant difference (
P
≤
0.001
). Conclusion. Training nurses based on EC clinical guidelines for anesthetized patients can improve the knowledge, attitude, and practice of ICU nurses. Evidence-based EC practice requires continuous training based on clinical guidelines and EC practice monitoring by nursing managers according to EC clinical guideline for an anesthetized patient.