The study assessed participants using questionnaires and scales according to three domains: personal baseline data, psychosocial factors (social anxiety, self-esteem, perceived discrimination), and quality of life. The personal baseline data were collected using a self-designed general demographic questionnaire, which included gender, age, ethnicity, residential area, only-child status, school enrollment type, parents’ educational attainment, and monthly household income (see Table 1). Psychosocial factors and quality of life were evaluated using the following four scales.

This study complied with the Declaration of Helsinki. The experimental research protocol, informed consent documents, questionnaire, and psychological evaluation form were reviewed and approved by the Institutional Review Board of the First Affiliated Hospital of Kunming Medical University in Yunnan Province, China. Ethics approval number: (2022) Lunsheng L No. 84.

Independent samples t-tests were performed on the scores for quality of life, self-esteem, social anxiety, perceived discrimination and all of their subdimensions between the pre-surgery group and the control group. The control group revealed significantly higher scores on quality of life, self-esteem, and their subdimensions (p < 0.001) compared to the pre-surgery strabismus group. Conversely, the control group had significantly lower scores in social anxiety, perceived discrimination, and their subdimensions compared to the pre-surgery group (p < 0.001). The effect size was calculated, and Cohen’s d > 0.5, indicating a medium-to-large effect (Table 4).

Patients with strabismus in the study were classified into constant exotropia, esotropia, intermittent exotropia and vertical strabismus. ANOVA revealed significant differences among the four strabismus types in quality of life, psychosocial scores, social anxiety, and its subdomains (fear of negative evaluation; social avoidance and distress). Further LSD testing demonstrated that intermittent exotropia had significantly higher quality of life (72.16 ± 18.11) and psychosocial (73.73 ± 18.38) scores than constant exotropia, esotropia, and vertical strabismus, however, there was no significant differences among the latter three types. The vertical strabismus group had the highest scores on the total social anxiety score and the two sub-dimensions (18.52 ± 5.03, 10.97 ± 3.36, and 7.55 ± 2.01, respectively), which were significantly higher than those of the other three groups, while there was no statistical difference among these three groups. There was no statistical difference in the scores of these four strabismus groups on self-esteem with sub-dimensions, discrimination perception with sub-dimensions. Calculating the partial η² of the effect size, we found that the effect sizes of variables with significant differences ranged from 0.03 to 0.06, indicating a generally moderate effect (Table 5).

Exotropia is denoted by a “-” mark, esotropia is denoted by a “+” mark, and prism diopters of strabismus is denoted by “Δ”mark. The same as below. We compared the impact of mild strabismus ( < 30Δ) and severe strabismus ( ≥ 30Δ) on quality of life and psychosocial factors. For exotropia, the mild group (-30Δ < ∼ ≤ -15Δ) showed significantly higher quality of life, self-esteem with its subdimensions scores (appearance, public morality, and helping others) than the severe group ( ≤ -30Δ) (p < 0.05); but showed lower scores on the social anxiety subdimension (social avoidance and distress) and individual discrimination perception scores than the severe group ( ≤ -30Δ) (p < 0.05) (Table 6).

For esotropia, the mild group (+10Δ ≤ ∼ < +30Δ) showed higher scores for quality of life, self-esteem with its subdimensions (appearance, sense of achievement, public morality, and helping others) than the severe group ( ≥ +30Δ), but showed lower scores for discrimination perception. The rest of the indicators were not affected by the prims diopters of strabismus (p > 0.05) (Table 7). This result show that the prims diopters of the exotropia and esotropia may influence the quality of life and social psychological factors.

Compared to the small prim diopters of the strabismus, the big ones may reduce the quality of life and self-esteem scores, increase the social anxiety and perceived discrimination scores. There is a little difference between the esotropia and exotropia. Through the calculation of the effect size Cohen’s d, variables with significant differences all have values above 0.5, indicating a moderate or above effect.

The data of strabismus patients before operation, 1 and 3 months after operation were analyzed by repeated measurement ANOVA. The results showed that the overall score and sub-dimension scores of patients’ quality of life and self-esteem were generally higher than those before operation. The score had an increasing trend 1 month after operation, but there was no significant difference. The score increased significantly 3 months after operation (P = 0.000). The ability sub-dimension of self-esteem was significantly improved at 1 and 3 months after operation [f(2,218) = 106.440, P = 0.000]; The sports sub-dimension of self-esteem decreased slightly at 1 month after operation, but increased significantly at the second follow-up at 3 months after operation [f(2,218) = 6.325, P = 0.002]; However, there was no significant difference in these 3 sub-dimensions of self-esteem: sense of achievement, discipline, merit and helping others. There was no significant difference in social anxiety and sub-dimension scores between the two groups at 1 month after operation, but it was significantly lower at 3 months after operation [f(1.878204.688) = 42.467, P = 0.000]. There was a certain difference in patients’ perception of discrimination after operation and before operation, but it did not reach the traditional statistical significance level (P = 0.056). The perception of individual discrimination decreased significantly at 1 and 3 months after operation [f(2,218) = 4.754, P = 0.010], and the perception of group discrimination decreased significantly at 3 months after operation [f(2,218) = 3.084, P = 0.048]. In this study, the effect bias η 2 of repeated measurement analysis of variance was calculated, and the results showed that both of them had medium and high response (see Table 8 for details).

This study found that children with strabismus have lower self-esteem and quality of life, higher levels of perceived discrimination and social anxiety compared to healthy peers of the same age. Overall, their mental health and quality of life are worse. This may be due to the fact that the appearance of strabismus can have negative impacts on interpersonal relationships. People with strabismus are often viewed as different by those around them and are subject to discrimination and exclusion. As a result, they may experience negative psychological emotions such as inferiority, anxiety, depression, and loneliness. In addition, strabismus in childhood can affect visual development, leading to amblyopia and stereoscopic vision disorders, which can result in decreased learning and motor abilities and affecting daily life (e.g., falling down stairs). This may aggravate the anxiety of strabismus patients, and their self-esteem is easily frustrated. This study found that patients with strabismus had lower self-esteem and quality of life scores than normal people, while their scores for social anxiety and perceived discrimination were higher. This is consistent with the results of low self-esteem, social phobia, depression and anxiety, and low quality of life of strabismus patients found by some scholars (Buffenn, 2021; Gouveia-Moraes et al., 2023; Schuster et al., 2019; Silva et al., 2022).

Children and adolescents aged 8–17 are in a critical period of character formation and physical and mental development. The negative effects of strabismus stem from poor visual development on the one hand and facial defects on the other, both of which are detrimental to children’s psychological development and increase the risk of psychological or mental illness. Therefore, it is essential to detect strabismus early and treat it surgically as soon as possible. This not only promotes visual and visual function development of children with strabismus but also helps to reverse the negative psychological effects caused by the appearance of strabismus, thereby improving the quality of life for patients with strabismus.

Some scholars have shown that esotropia has a greater impact on interpersonal relationships than exotropia, especially in case of big angles esotropia, which tends to receive more negative evaluations (Goff et al., 2006; Olitsky et al., 1999). While studies on vertical strabismus are less common. The results of this study differ from those of previous studies. We compared patients with strabismus into four categories: constant exotropia, esotropia, intermittent exotropia, and vertical strabismus. This study found that among these four types of strabismus, intermittent exotropia has better mental health and quality of life than other types of strabismus. Intermittent exotropia scored highest on the quality-of-life scale, while vertical strabismus scored lowest on the social anxiety scale. It is possible to analyze that intermittent exotropia is a type of mild strabismus, which can self-control the normal position. Exotropia only appears when looking at the distance or distracting. The appearance of strabismus is not a permanent condition and there is no different from normal people, so the impact of appearance is less than of other types of strabismus. Furthermore, the likelihood of amblyopia developing in intermittent exotropia is lower. Patients typically have some stereoscopic vision and relatively good visual function, which means that the impact on daily activities is less than with other types of strabismus. Therefore, patients with intermittent exotropia tend to have better mental health and quality of life than those with other types of strabismus. Vertical strabismus, the appearance is characterized by uneven eye height, tilted neck and asymmetrical facial development. Some cases even involve scoliosis. Visual symptoms include double vision, amblyopia, lack of stereoscopic vision, and refractive errors. Vertical strabismus has the worst visual function and appearance defects among the four types of strabismus, and is much more likely to cause anxiety and inferiority in patient. This is consistent with the results of our study, which showed that vertical strabismus had the highest social anxiety score and a relatively low quality of life score. In addition, most types of strabismus patients are more sensitive and have low self-esteem. Their self-esteem is easily frustrated and they are easy to perceive discrimination from individuals or groups. The results of this study found that there was no significant difference in the scores of self-esteem, discrimination and its sub-dimensions.

The study found that the degree of strabismus also has a great correlation with social psychological factors. The more severe the strabismus, the more obvious the appearance defects will be; at the same time, the greater the impact on visual function and mental health. For example, Uretmen et al. (2003) found that children with severe strabismus are more susceptible to discrimination, particularly with esotropia causing greater harm to self-esteem. We also found that the degree of strabismus was correlated with quality of life and social psychological factors. Patients with mild strabismus (below 30Δ) scored higher in quality of life and partial self-esteem, and lower in social anxiety and perceived discrimination compared to those with severe strabismus (above 30Δ). There are certain differences in the psychological impact of esotropia and exotropia. These differences may be caused by the appearance and visual function between the two types of strabismus: exotropia gives people the impression that the person is not looking at them directly and is disrespectful, while esotropia gives people the impression that the person is selfish and narrow-minded. In terms of visual function, exotropia does not easily cause amblyopia, but it lacks stereopsis; while esotropia easily causes amblyopia, but has partial stereopsis. As the angle of strabismus increases, patients are more likely to experience significant social anxiety and feeling of discrimination, which can reduce their quality of life and affect the normal social interactions in daily life.

Previous studies in other countries have shown that surgery has positive effects on the mental health and quality of life for patients with strabismus (Archer et al., 2005). However, there is a lack of relevant research in China. For example, Ehlers et al. (2023) found through a questionnaire survey that patients’ quality of life related to strabismus improved 3 months after strabismus surgery, while anxiety and depression levels decreased. Menon et al. (2002) surveyed 40 strabismus patients aged 15–25 3 months after surgery and found that 95% of patients perceived a significant improvement in their self-confidence and self-esteem. Xu et al. (2012) also found that Chinese adolescents and adults with strabismus experienced significant improvements in self-esteem, self-confidence, and interpersonal relationships 2–3 months after undergoing strabismus correction surgery. Strabismus correction surgery primarily serves an aesthetic purpose. Improving the appearance of strabismus can prevent others from forming preconceived stereotypes and negative evaluations, thereby reducing the perception of discrimination among strabismus patients. Secondly, early surgery for children with strabismus can prevent the occurrence of strabismic amblyopia and promote the formation of normal stereoscopic vision, which is beneficial to improving their quality of life. Mojon-Azzi et al. (2011) believe that negative attitudes toward strabismus patients among peers appear around the age of 6, so having strabismus surgery before the age of 6 is more beneficial to their physical and mental health development. Another study even found that changes in the quality of life of children with strabismus can also promote changes in the quality of life of their parents (Temeltürk et al., 2022).

This study shows that strabismus surgery has very positive effects on changes in quality of life and mental health, but there is a certain degree of delay. According to the statistical results, the quality of life and self-esteem were not significantly improved 1 month after operation, and even the score of physical exercise was decreased, but the quality of life and self-esteem were significantly improved 3 months after operation. Social anxiety did not change significantly at 1 month after operation, but improved significantly at 3 months after operation. The perception of discrimination was improved after operation, but it did not reach the traditional level of statistical significance. However, the sub-dimension scores of individual discrimination perception were significantly improved at 1 and 3 months after operation, while the group discrimination perception scores were improved at 3 months. We believe that after strabismus surgery for a period of time, mainly 3 months, the positive self-esteem is increasing, the negative anxiety and discrimination perception are decreasing, and the quality of life has been significantly improved. The change was not obvious at 1 month, which is a major feature of this study different from other studies. The effect of surgery on self-esteem was also limited, and there was no significant change in the three dimensions of sense of achievement, discipline, merit and help. The surgery improved patients’ appearance and visual function, enhanced their social adaptation abilities and quality of life, and helped restore their confidence and self-esteem.

Strabismus is a disease involving ophthalmology and psychology. From an ophthalmological perspective, the effectiveness of treatment is primarily assessed based on the recovery of eye position and visual function. However, from a psychological perspective, assessing the effectiveness of treatment also requires evaluating changes in patients’ mental health and quality of life. Hatt et al. (2012) study found that 95% of strabismus patients achieved successful surgeries based on traditional surgical criteria, but when postoperative quality of life improvement was added into the criteria for successful treatment, this proportion dropped to 50%. This explains why many strabismus patients, even after successful surgery, still stubbornly believe that their eyes remained in a strabismus state and have not been completely cured. They still experience feelings of discrimination and a lack of respect from others. Therefore, surgery is a primary treatment for strabismus, and psychological intervention can further improve the effectiveness of treatment. According to the results of this study, psychological intervention is recommended to be implemented about 1 month after strabismus surgery, which is more conducive to improving the mental health level of strabismus patients. In addition, it is essential to quantitatively assess the mental health and quality of life of strabismus patients before and after surgery, as this can serve as a basis for psychological intervention and counseling for strabismus.

This study involves ophthalmology and psychology, examining the dynamic changes in quality of life and psychosocial factors in patients 1 and 3 months after strabismus surgery with a large sample size. Compared to previous studies that only classified strabismus into exotropia and esotropia, this study provides a more detailed classification of strabismus types and degrees. Focusing on the less being explored area of discrimination perception in children with strabismus, this study reflects the psychological and personality characteristics of strabismic children in ethnic minority areas in Southwest China. Currently, research on strabismus related psychology in China is relatively scarce compared to other developed countries worldwide, especially in ethnic minority areas in Southwest China, where such research is still lacking. The results of this study also fill this gap.