Objectives To investigate the effects of visual pretreatment on the prevention of emergence delirium from general anesthesia in children undergoing ophthalmic operation. Methods A total of 132 child patients, American Society of Anesthesiologists (ASA) Ⅰ or Ⅱ , aged 2‒6 y, weighing 11‒21 kg, boys or girls, who were scheduled for bilateral chalazion resection under general anesthesia were selected. According to the random number table method, they were divided into three groups: a visual preconditioning group (group A), a drug treatment group (group B) and a control group (group C). Patients in group A wore an eye patch two days before operation (≥2 h/d). Groups B and C were pumped with 0.5 μg/kg dexmedetomidine (Dex) or an equal volume of normal saline respectively, at the beginning of anesthesia induction over 15 min. Their modified Yale Preoperative Anxiety Scale (m‑YPAS) score, operation time, the time of spontaneous breathing recovery, extubation time, the length of stay in post‑anesthesia care unit (PACU), the incidence of pain and delirium in PACU, the incidence of postoperative nausea and vomiting were recorded. The levels of plasma cortisol (Cor), norepinephrine (NE), blood glucose (Glu), heart rate and mean arterial pressure (MAP) were measured before anesthesia induction and 1 hour after operation. Results There was no statistical difference in m‑YPAS scores, operation time, the time of spontaneous breathing recovery, the incidence of pain in PACU, and the incidence of nausea and vomiting after surgery among the three groups (P>0.05). Groups A and C presented shorter extubation time than group B (P<0.05). Groups A and B showed decreases in the length of PACU stay and the incidence of delirium, compared with group C (P<0.05), but there was no statistical difference between groups A and B (P>0.05). There was no statistical difference in Cor, NE, Glu, heart rate, and MAP among the three groups before anesthesia induction (P>0.05). Furthermore, 1 h after operation, Cor, NE, heart rate and MAP in group A and B were significantly lower than those in group C (P<0.05), but there was no significant difference between groups A and B (P>0.05). The difference in Glu among the three groups was not statistically significant (P>0.05). Conclusions The use of eye mask for children before bilateral chalazion operation can reduce the incidence of delirium and relieve stress response, with similar effects with Dex but shorter extubation time.