Myopia, or nearsightedness, is becoming a worldwide public health crisis. In the United States, about one-third of the population has myopia and the prevalence is increasing.
“Knowing your children’s potential risk of myopia and taking action before it’s too late can benefit their academic and athletic performance, personal growth and overall health.”
Parents tend to wait until their child shows signs of visual difficulty. These can include not being able to see the whiteboard in school (66%), squinting more than normal (62%) and holding materials far away (52%).
Global Myopia Awareness Coalition (GMAC) states that screening by the pediatrician is insufficient and that all children should be have a comprehensive exam by an eye care specialists to avoid the risk of vision problems later in life.
Myopia occurs in more than 50% of the population in many industrialized countries and is expected to increase; complications associated with axial elongation from myopia are the sixth leading cause of blindness.
The prevalence of myopia is higher in individuals whose both parents are myopic, suggesting that genetic factors are clearly involved in myopia development. At the same time, population studies suggest that development of myopia is associated with education and the amount time spent doing near work; hence, activities increase the exposure to optical blur as well as an interplay between genetic and the environmental factors.
Myopia prevalence varies greatly in different ethnic and geographical populations . Recent studies of American preschool children (aged 6–72 months) revealed a prevalence of:
- 1.2% in non-Hispanic whites
- 3.7% in Hispanics
- 3.98% in Asians
- 6.6% in African Americans
Among older children, the difference between Asian and Caucasian populations is obvious; a study of Australian adolescents reported prevalence of 42.7% in 12 yr old and 59.1% in 17 yr old children of East Asian ethnicity, compared to 8.3% in 12 yr old and 17.7% in 17 yr old children of European Caucasian descent.
If both parents of a child are myopic, their child will have about a 50 percent or greater chance of becoming myopic too. A non-myopic child with two myopic parents spends two or more hours per day outside, the child will decrease his chances of having myopia to that of having no myopic parents. However, once a child develops myopia, being outdoors will not slow the progression of the condition.
Factors for myopia in schoolchildren included low outdoor time and near work, dim light exposure, the use of LED lamps for homework, low sleeping hours, reading distance less than 25 cm and living in an urban environment. Spending more time outdoors may also help improve mood. However, we should make sure that children are taking proper sun precautions like using sunscreen and wearing sun glasses.
The eye will continue to grow disproportionately longer, which can cause complications, including retinal detachments, later in life. Therefore, we should make an effort to have young children spend some time outdoors every day.
Children with early onset are at particular risk of complications associated with myopia, as progression over time might result in high myopia and myopic macular degeneration. Both genetic and environmental factors play a role in the increasing prevalence of myopia.
. Andrzej Grzybowski, et al A review on the epidemiology of myopia in school children worldwide Ophthalmology volume 20, Article number: 27 (2020) https://bmcophthalmol.biomedcentral.com/articles/10.1186/s12886-019-1220-0