Myopia, or nearsightedness, means that a person sees close objects clearly, but objects that are farther away appear blurred. Someone with myopia might notice difficulty focusing on a TV or movie screen, or the blackboard in school. A recent study suggests that more school children should be screened for this vision problem, particularly in light of the effect it can have on school performance.

Myopia is diagnosed by an eye examination and is usually corrected by wearing glasses or contact lenses. There are also surgical options for more extreme cases of myopia. Myopia often starts gradually, during school age and may progress in severity into the 20s.

Children should be routinely screened at their health checks ups and parents should alert their children’s doctors and request a vision screening and potential eye doctor referral if they notice their children squinting at TV and movie screens or sitting unusually close to them.

A group of U.S. researchers assessed the development of myopia during the period from 1989-2009 in a group of 4927 school children aged five to 16 years. They wanted to know how many children actually developed myopia, at what age it was most common, and whether the child’s sex or ethnicity influenced their likelihood of becoming nearsighted.

The children underwent standardized eye exams throughout the study period. Although the exact measurements for diagnosing myopia can vary, these researchers chose a cutoff measurement that was most likely to affect school work, TV viewing, and playing sports. This was also the measurement at which most practitioners would prescribe glasses for the patient. Because the researchers wanted to be sure to capture the impact of ethnicity on the risk of myopia, they used multiple study sites, including Alabama, California, Arizona, and Texas and specifically made sure the study included at least 500 African American, Native American, Asian, Hispanic, and white children.

The study revealed that at least one in six children (16.4%) had developed myopia by age 16 and that each ethnic group had at least 11% children who became myopic. Specifically, there were 749 children who were diagnosed with myopia by the end of the study. New cases occurred in 27.3% of Asians, 21.4% of Hispanics, 14.5% of Native Americans, 13.9% of African Americans and 11% of whites.

Previous studies had suggested that new cases of myopia peak between ages 10-12 years. This study supported that finding. Myopia was only found in a small percentage of children who were 7 years old and more than 75% of the new cases occurred between ages 9-13. Girls were more frequently myopic than boys (18.5% compared with 14.5%) .The researchers suggested that this may be because girls mature physically earlier than boys do. The study did not reveal an association between low birth weight and myopia, but rather found that myopia was higher in children with normal birth weight.

The investigators maintain that their study, published in The Archives of Ophthalmology, supports other research and shows that myopia develops commonly in the school-aged population, peaking in early adolescence. They point out that vision care is often not a covered medical service for school aged children which leaves them vulnerable to a potentially treatable condition which can negatively impact academic, athletic, and social functioning.

Children should be routinely screened at their health check-ups and parents should alert their children’s doctors and request a vision screening and potential eye doctor referral if they notice their children squinting at TV and movie screens or sitting unusually close to them, or if they are doing poorly in school or their teachers report difficulties with distance work.