The Prevalence Of Myopia Among Chinese University Students

Myopia, or short-sightedness, is a widespread issue among Chinese students, with nearly 60% of students aged 6 to 18 being myopic. This proportion increases with age, affecting 80% of senior high school students. The problem is even more pronounced among university students, with rates of myopia reaching 80% in some cities. A study of 5060 Chinese university students in Shanghai found that 95.5% were myopic, with 19.5% being highly myopic. This high prevalence of myopia is concerning and has sparked efforts to address the issue.

Prevalence of myopia in Chinese university students

Myopia, or short-sightedness, is a common condition in China, particularly among students. The condition is known to be caused by a combination of genetic and environmental factors, with the latter including reduced time outdoors and increased academic pressure.

Prevalence in Chinese students

Nearly 60% of students aged 6 to 18 across China are myopic, according to a study by researchers from Shanghai's East China Normal University. The incidence increases with age, affecting about a third of primary school students, 65% in junior high, and 80% in senior high school. In smaller cities, nearly 70% of students are myopic, compared to 56% in major cities.

Prevalence in Chinese university students

The prevalence of myopia is even higher among Chinese university students, with rates of up to 80% reported in large cities like Guangzhou. A study of 5,060 Chinese university students in Shanghai found that 95.5% were myopic, with 19.5% being highly myopic. Another study, with a sample size of 273,006 individuals, found that the prevalence of myopia increased dramatically from 23.13% at age 5 to 82.83% at age 11, stabilizing at 80% at age 17 and above.

Contributing factors

The high prevalence of myopia among Chinese university students is influenced by various factors. These include:

• Academic pressure: Chinese students often face intense pressure to perform academically, leading to increased time spent indoors studying and less time outdoors.
• Reduced outdoor activity: Spending more time outdoors and being exposed to natural light can help prevent the onset of myopia. However, many Chinese students have limited opportunities for outdoor activities due to their heavy academic workload.
• Genetic factors: Parental myopia is an independent factor contributing to the incidence of myopia in their children.
• Use of electronic devices: Increased use of smartphones and other digital devices is associated with a higher risk of developing myopia.
• Gender: In the Shanghai study, being female was associated with a higher probability of myopia, although other studies have found conflicting results.

Prevention and control

Given the high prevalence of myopia among Chinese university students, prevention and control measures are essential. These include:

• Reducing time spent on electronic devices: Encouraging students to limit their screen time and spend more time outdoors can help prevent the onset and progression of myopia.
• Promoting outdoor activities: Schools can play a role in encouraging outdoor activities by ensuring that students participate in regular physical education classes and outdoor recreation.
• Regular eye examinations: Early detection through regular eye exams can help identify myopia and allow for appropriate interventions to prevent further progression.

Risk factors for myopia

Myopia, or short-sightedness, is a common refractive disorder that occurs when the eye cannot focus on distant objects. The prevalence of myopia is increasing globally, with nearly half of the world's population projected to be myopic by 2050. This condition is particularly prevalent in East and Southeast Asia, with nearly 60% of students aged 6 to 18 in China suffering from myopia.

There are several risk factors associated with the development and progression of myopia, including both genetic and environmental factors. Here are some key risk factors for myopia:

Genetic Factors:

• Family history: The risk of developing myopia increases significantly if one or both parents are myopic.
• Genetic syndromes: Certain genetic syndromes, such as Marfan syndrome and Knobloch syndrome, are associated with high myopia, although these forms are relatively rare.

Environmental Factors:

• Education: Higher levels of education and academic pressure are strongly correlated with myopia prevalence. Intensive studying and near-work activities, such as reading and writing, are risk factors for myopia development.
• Screen time: The use of digital devices, such as smartphones and tablets, has been linked to an increased risk of myopia. However, more research is needed to establish a direct causal relationship.
• Time spent outdoors: Reduced time spent outdoors and engaging in sports activities is a risk factor for myopia. Increasing time spent outdoors, especially in bright sunlight, is recommended to reduce the risk of myopia.
• Urban environment: Living in urban areas is considered a risk factor for myopia, possibly due to the interplay of educational and lifestyle factors.
• Income and socioeconomic factors: Higher family income and socioeconomic status have been associated with a higher prevalence of myopia.

It is important to note that the development of myopia is influenced by a combination of genetic and environmental factors, and individual susceptibility can vary. Early interventions, such as spending more time outdoors, taking regular breaks during near-work tasks, and receiving eye check-ups, can help mitigate the risk of myopia development.

Gender differences in myopia rates

Myopia is a growing problem in China, with nearly 60% of students aged 6 to 18 suffering from the condition. This is a much higher proportion than in the West, where the rate hovers around 10%. The incidence of myopia increases with age, with about a third of primary school students suffering from myopia, 65% in junior high school, and 80% in senior high school.

Several studies have found that there are gender differences in myopia rates, with females having a higher prevalence of myopia than males. This difference becomes more pronounced with age, with girls having a higher prevalence of myopia from age 9 onwards. One study found that the incidence of myopia in females is 1.679 times higher than in males.

The reasons for this gender disparity are not entirely clear but may be due to differences in behaviour and habits between boys and girls. Girls tend to spend more time studying and less time participating in outdoor activities than boys. This is supported by the finding that parental myopia is also a risk factor for myopia in children, as eye health is closely related to genetics and environment.

The high prevalence of myopia among Chinese students, particularly females, is a cause for concern and highlights the need for effective prevention and control measures.

Impact of outdoor activities on myopia

Outdoor activity has been shown to have a significant impact on the development of myopia in children and adolescents. Spending more time outdoors and reducing time spent on near work activities such as reading or using electronic devices can help prevent the onset and progression of myopia.

Evidence from Research Studies

Several research studies have demonstrated the protective effect of outdoor activity against myopia. A meta-analysis of clinical trials, cohort studies, and cross-sectional studies found that increased time outdoors was associated with a reduced risk of incident myopia. The analysis also showed that outdoor time was effective in slowing the myopic shift in refractive error but did not have a significant effect on slowing the progression of myopia in eyes that were already myopic.

Another study conducted in Northeast China found that increasing outdoor activities prevented the onset and development of myopia, as well as axial growth and elevated intraocular pressure in children. The intervention group, which was allowed additional time outside the classroom, had a significantly lower incidence of myopia and changes in refractive error towards myopia compared to the control group.

A population-based survey of school-aged children in Sydney, Australia, also found that higher levels of outdoor activity were associated with more hyperopic refractions and lower myopia prevalence. Students who spent more time outdoors and less time on near work activities had more hyperopic mean refraction, while those who spent more time on near work and less time outdoors had the least hyperopic mean refraction.

Impact of Outdoor Activity on Myopia in Chinese Students

The prevalence of myopia among Chinese students is particularly high, with nearly 60% of students aged 6 to 18 being myopic. This is much higher than the rate in similar age groups in the West, which hovers around 10%. The high prevalence of myopia in Chinese students is attributed to the intense academic pressure and the resulting increase in time spent indoors, depriving children of the sunlight necessary for healthy eye development.

A study of Chinese adolescents found that regular physical activity was an independent factor in reducing the incidence of myopia. Other factors, such as daily time spent on in-school and after-school physical activities, eye exercises, and a positive attitude towards physical education, were also found to be protective against myopia.

A report released in 2023 revealed that the overall prevalence of myopia among Chinese students in primary and secondary schools had reached 64.85%. The prevalence was higher in middle and high school students (78.18% and 87.05%, respectively) compared to primary school students (54%). The study also found a higher prevalence of myopia in girls than in boys.

Academic pressure and myopia development

Academic pressure and a reliance on technology have contributed to China having one of the highest childhood myopia rates in the world. In 2018, over half of the country's minor population were myopic, according to official statistics. The rate is increasing, especially among students.

Myopia, or short-sightedness, is caused by the eyeball becoming too long, so that light is focused in front of the retina, making distant objects appear blurry. It is one of the leading causes of visual impairment worldwide, and if left untreated, can develop into more serious conditions.

In China, the pressure to perform academically means that children spend most of their time indoors, depriving them of the sunlight that allows their eyes to develop healthily. The incidence of myopia increases as Chinese children get older: about a third of primary school students suffer from myopia, rising to 65% in junior high school, and 80% in senior high school.

The problem is not unique to China. In 2020, the World Health Organization (WHO) stated that East Asian countries had the highest rates of myopia worldwide, with 75% of the adult population affected. A 2012 study in Seoul, South Korea, found that 96.5% of 19-year-old men were nearsighted.

The link between academic pressure and myopia is clear. In Japan, a less intense school curriculum was introduced nationally in 2012 based on a pressure-free education policy. The degree of myopia and the prevalence of high myopia increased with the passage of time under the high-pressure education system; however, no myopia progression was observed after the introduction of the pressure-free system.

In China, the government has recognized the problem and is attempting to address it. In 2018, reducing myopia rates became a national priority, with Beijing vowing to bring them to under 60% in junior high schools and under 70% in senior high schools by 2030. However, the race to prevent a generation from coming of age with nearsightedness is inextricably tied to education models and the pressure to succeed.

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