Lazy eye condition in childhood increases the risk of developing obesity, hypertension, metabolic syndrome, and heart attacks in adulthood, a new study revealed.

Amblyopia or lazy eye is a neurodevelopmental condition that causes reduced vision in one eye. It develops when the brain and eye coordination break down, causing the brain to increasingly rely on the stronger eye, leading to deterioration of vision in the weaker eye.

The signs of the condition include wandering inward or outward of one eye, squinting of one eye, poor depth perception, head tilting, and poor vision. As the condition typically impacts just one eye, many children may not notice any issues with their vision until their routine vision tests.

In a study published in the journal eClinicalMedicine, researchers identified a correlation between the lazy eye in childhood and increased health risk later in adulthood. However, the study does not show a causal relationship between them.

"Amblyopia is an eye condition affecting up to four in 100 children. In the U.K., all children are supposed to have vision screening before the age of five to ensure a prompt diagnosis and relevant ophthalmic treatment," said corresponding author, Professor Jugnoo Rahi.

"It is rare to have a 'marker' in childhood that is associated with increased risk of serious disease in adult life, and also one that is measured and known for every child—because of population screening. The large numbers of affected children and their families may want to think of our findings as an extra incentive for trying to achieve healthy lifestyles from childhood," Rahi added.

The study examined more than 126,000 participants between the ages of 40 and 69, who were part of the UK Biobank cohort who had undergone ocular examination.

During the recruitment, participants were inquired if they had been treated for amblyopia in childhood and if they still had the condition. They were also asked about medical diagnoses related to diabetes, high blood pressure, and cardio/cerebrovascular conditions, including angina, heart attack, and stroke. The BMI (body mass index), blood glucose, and cholesterol levels of the participants were measured, and their mortality was tracked.

Out of 3,238 participants who reported having a lazy eye as a child, 82.2% had reduced vision in one eye even as an adult.

"The findings showed that participants with amblyopia as a child had 29% higher odds of developing diabetes, 25% higher odds of having hypertension, and 16% higher odds of having obesity. They were also at increased risk of heart attack—even when other risk factors for these conditions (e.g., other diseases, ethnicity, and social class) were taken into account," the news release stated.

The researchers observed an elevated risk of health issues not only in individuals who continued to experience vision problems but also to a certain extent in participants who had amblyopia during childhood and maintained normal vision in adulthood, though the association was not strong.

"Vision and the eyes are sentinels for overall health – whether heart disease or metabolic dysfunction, they are intimately linked with other organ systems. This is one of the reasons why we screen for good vision in both eyes. We emphasize that our research does not show a causal relationship between amblyopia and ill health in adulthood," said the first author, Dr. Siegfried Wagner.

"Our research means that the 'average' adult who had amblyopia as a child is more likely to develop these disorders than the 'average' adult who did not have amblyopia. The findings don't mean that every child with amblyopia will inevitably develop cardiometabolic disorders in adult life," Wagner added.