Start early for a lifetime of good vision and healthy eyes

If your mother told you to eat your carrots so you’d be able to see in the dark, she was right. It turns out that feeding kids carrots is just one of a number of things parents can do to promote a lifetime of healthy eyes and good vision.

Other things include regular eye exams, and sunglasses or hats to shade kids’ eyes, experts say.

While so-called refractive error (that is, the need for vision correction) and eye disease is sometimes hereditary, and some eye disease is congenital, some issues are preventable, said Dr. Ron Weber, an Atlanta-based ophthalmologist.

For example, myopia, or nearsightedness, “not only has a genetic component but is also influenced by how kids use their eyes during childhood,” he told Reuters Health by phone.

He said that extended close work, such as reading, has long been suspected to cause nearsightedness. Recent support for the association has come from a study in which people with a higher level of education were more likely to have myopia, purportedly because they spend more time reading or working on computers. Another study showed that children who spend more time outdoors are less likely to become myopic.

But these findings don’t mean kids should be discouraged from reading or working on the computer. Instead, Weber suggests, make sure a child’s environment is well-lit while they are doing close work. Parents should also help kids get into the habit of holding their reading material at the optimal distance - about 18 to 22 inches, he said. Finally, taking a break every five minutes or so, to let the eyes relax and focus on an object in the distance, will also help.

Education influences the role of genetics in myopia Myopia is a complex inherited ocular trait resulting from an interplay of genes and environmental factors, most of which are currently unknown. In two independent population-based cohorts consisting of 5,256 and 3,938 individuals from European descent, we tested for biological interaction between genetic predisposition and level of education on the risk of myopia. A genetic risk score was calculated based on 26 myopia-associated single nucleotide polymorphisms recently discovered by the Consortium for Refractive Error and Myopia. Educational level was obtained by questionnaire and categorized into primary, intermediate, and higher education. Refractive error was measured during a standardized ophthalmological examination. Biological interaction was assessed by calculation of the synergy index. Individuals at high genetic risk in combination with university-level education had a remarkably high risk of myopia (OR 51.3; 95 % CI 18.5–142.6), while those at high genetic risk with only primary schooling were at a much lower increased risk of myopia (OR 7.2, 95 % CI 3.1–17.0). The combined effect of genetic predisposition and education on the risk of myopia was far higher than the sum of these two effects (synergy index 4.2, 95 % CI 1.9–9.5). This epidemiological study provides evidence of a gene-environment interaction in which an individual’s genetic risk of myopia is significantly affected by his or her educational level.