Nearsightedness is a common cause of blurred vision. Objects in the distance appear blurry and out of focus for nearsighted people. A new study has suggested that first-born children run higher risk of becoming nearsighted later in life, compared with their later-born siblings.
The researchers suggested that parents pushing the eldest kid to do better in studies may be partly blamed for the higher myopia risk among the first-borns. Study author Jeremy Guggenheim, of Cardiff University in Britain, said, "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."
For the study, the research team examined birth order and nearsightedness in about 89,000 people, ages 40 to 69, in Britain. They observed that first-borns were 10% more likely to be nearsighted and 20% more likely to be severely nearsighted than their subsequent siblings.
The researchers said, "Reduced parental investment in education of children with later birth order may be partly responsible. Education accounted for about 25% of the link between birth order and the risk of nearsightedness. However, in addition to education, there may be other, unmeasured factors that could partially mediate the relationship between birth order and one's risk of nearsightedness."
The study was published in JAMA Ophthalmology.