A new study found that the risk of becoming nearsighted is somewhat higher in firstborn children, as opposed to the other younger siblings.
Researchers analysed the cases of nearsightedness, also known as myopia, in 89,000 adults ages 40 to 69, while also looking at birth order. The results shows that the firstborn participants’ risk of being nearsighted was increased by 10 percent, compared with the later-born individuals. The risk of becoming severely nearsighted increased by almost 20 percent in the firstborn participants, according to the researchers.
The new study also found that education, birth order, and risk of nearsightedness had something in common. In most cases, the firstborn individuals had the highest educational degrees. According to the researchers, birth order, education, and risk of nearsightedness were linked in 25 percent of the cases.
When it comes to their firstborn child, parents may invest more effort and time in their education, which means that firstborn children may engage in more activities – excessive reading, working on a computer, or any other activity that might cause visual stress – that increase the risk of myopia.
“Our study provides an extra piece of evidence linking education and myopia, consistent with the very high prevalence of myopia in countries with intensive education from an early age,” Jeremy A. Guggenheim, a professor in optometry and vision sciences at Cardiff University in the United Kingdom, stated.
Another study that was conducted in China involved about 1,900 children, and after looking at them the researchers found that more time spent outdoors lowered the risk of becoming nearsighted.
In a previous study that was published in the Singapore Medical Journal, researchers looked at about 110,000 people ages 15 to 25, and found that nearsightedness was more prevalent in those who had more years of formal learning.
About 30 percent of the participants involved in the new study, were nearsighted. Nowadays, myopia is a lot more common in younger people and it is slowly becoming a severe public health issue in many parts of the world.
Myopia or nearsightedness can also appear due to genetics, but otherwise it is triggered by doing activities that cause visual stress by tiring the eyes.
The researchers stated that the risk of nearsightedness and birth order may be linked by other factors as well, apart from education.
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