Myopia, or nearsightedness, is a visual condition in which objects at a distance appear blurry while items closer to you are clearer.

According to recent research, the prevalence of myopia is increasing worldwide among all ethnicities and age groups, affecting approximately 2 billion people worldwide by 2050. This increase in myopia rates may be a result of a combination of genetic and environmental factors. In this article, we will discuss why myopia rates are increasing around the world.

What Is Myopia?

Myopia is a common visual condition that occurs when the eyeball is too long or the cornea is too curved. This results in light rays focusing in front of the retina instead of directly on it, causing distant objects to appear blurry.

Myopia typically develops during childhood and adolescence and tends to worsen until around age 20.

Why Are Myopia Rates Increasing?

Urbanization and Decreased Time Spent Outdoors

One of the most prominent reasons why myopia rates are increasing around the world is the unprecedented rate of global urbanization. According to the United Nations, more people live in urban areas than in rural areas as of 2021.

With this urbanization comes decreased time spent outdoors, a factor that has been shown to contribute to the development of myopia.

A study conducted in Taiwan showed that children who spent more time outdoors had a lower likelihood of developing myopia than those who spent more time indoors.

Similarly, a study in New Zealand found that children who played more sports outdoors had lower myopia rates than those who played more indoor sports.

The exact mechanism behind this relationship is still under study. One theory is that the bright outdoor light stimulates the release of dopamine, a neurotransmitter that helps regulate eye growth.

In contrast, indoor lighting may not produce enough dopamine, causing the eye to grow excessively and resulting in myopia.

Increased Screen Time

Another factor that may be contributing to the rising myopia rates worldwide is increased screen time. With the rise of technology, people are spending more time than ever on screens, such as computers, tablets, and smartphones.

This excessive screen time may be causing eye strain, which can lead to myopia.

A study conducted in Singapore found that children who spent more time using electronic devices had a higher risk of myopia.

The study suggests that using electronic devices from a young age may cause the eyes to become overly focused on close objects, leading to myopia.

Genetic Factors

While environmental factors such as urbanization, decreased time spent outdoors, and increased screen time may be contributing to the rise in myopia rates, genetic factors play a significant role in the development of myopia.

Myopia tends to run in families and is more common among certain ethnic groups, such as East Asians.

In recent years, several genes linked to myopia have been identified, including those involved in eye development and neurotransmitter signaling pathways. These genetic factors may interact with environmental factors to cause myopia.

Education and Academic Pressure

One theory suggests that academic pressures associated with higher education may also be contributing to the increased myopia rates.

A study conducted in China found that students in areas with higher academic competitiveness had higher myopia rates than those in areas with lower academic competitiveness.

This theory suggests that the emphasis placed on academic performance may cause students to spend more time on close work, such as reading and studying, which may contribute to myopia development.

Additionally, students may be under intense academic stress, leading to poor sleep habits, which may also contribute to the development of myopia.

What Can Be Done?

Although the exact causes of myopia are still being studied, there are ways to prevent or slow down its development. One of the most effective ways is to spend more time outdoors.

Children should spend at least two hours per day outdoors, according to experts.

In addition to spending more time outdoors, limiting screen time and taking frequent breaks when using electronic devices can also help prevent myopia.

Additionally, maintaining a healthy diet that includes eye-healthy nutrients such as omega-3 fatty acids, lutein, and zeaxanthin, can support healthy eye development.

Conclusion

The prevalence of myopia is increasing worldwide, and a combination of genetic and environmental factors may be contributing to this rise.

Urbanization, decreased time spent outdoors, increased screen time, academic pressure, and genetic factors all play significant roles in the development of myopia. While the exact causes are still being studied, spending more time outdoors, limiting screen time, and maintaining a healthy diet can all help to prevent or slow down myopia development.