Chances of Being Nearsighted Are Higher for Firstborns

Chances of being nearsighted are higher for firstborns than for their younger siblings, increasing by approximately 20 percent.

A new study conducted by researchers with the Cardiff University Eye Clinic, U.K. suggests that if you’re the first child in the family, chances that you will develop nearsightedness or myopia are higher than for your younger siblings. The correlation has been placed in the limelight before. Yet, researchers are weary of establishing a causality relation as well. However, the findings, published in the JAMA Ophthalmology outline an interesting framework for future studies.

The large-scale research, led by professor of vision sciences and optometry Jeremy Guggenheim, included a thorough analysis of medical records of approximately 90,000 people. The data was retrieved from the UK Biobank longitudinal survey. All participants were aged 40 to 69.

The results obtained after the research team combined demographic data with ophthalmological medical history and behavioral data pointed to the fact that chances of being nearsighted are higher for firstborns.

In fact, firstborns are 10 percent more likely to develop myopia in time. The risk of developing severe myopia or severe nearsightedness increased by 20 percent for firstborns compared to their younger siblings. The results held even after other relevant factors were adjusted for. Younger siblings were less likely to develop myopia and even less so severe nearsightedness.

This ophthalmological condition affects millions of people worldwide. Recent reports coming from China or India suggest that here the number of people affected by myopia has increased severely over the last decade. Typically, nearsightedness develops during early childhood and throughout adolescence. Depending on the severity grade, it can be corrected either by surgery or by prescription contact lenses or glasses. In the most severe cases, myopia may lead to glaucoma, retinal degeneration and other conditions that permanently affect sight.

The research team suggests that there may be a possible link between education and developing nearsightedness. When adjusting for the level of education of the participants in the study, the team found that firstborns with higher degrees were 25 percent more likely to be nearsighted.

As such, the fact that chances of being nearsighted are higher for firstborns is supported by the theory that a family’s investment in the educational process of their firstborn children may lead to them being more exposed to activities that strain their eyes.

The study also suggests that younger siblings aren’t subject to as much pressure regarding their educational results. As a results, they tend to engage less in activities that promote the development of nearsightedness.

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