By Beth Longware Duff; reviewed by Pirindhavellie Govender-Poonsamy, B.Optom, M.Optom, CAS

Nearsightedness is the most common distance refractive error among children and young adults. It occurs in 30% to 40% of adults in the U.S. and Europe and in up to 80% to 90% of the Asian young adult population. The medical term for nearsightedness is myopia.

The prevalence of myopia has been increasing rapidly in recent decades. Researchers predict that by the year 2050, about half of the world's population will have myopia.

People who are nearsighted see close objects more clearly than they see distant objects. This is because when light enters their eyes, it comes to a focal point in front of the retina instead of directly on it.

The exact cause of the global increase in nearsightedness is unknown, but genetics clearly play a role. Studies have identified almost 200 genetic factors for refractive error and myopia. When one or both parents have myopia, there is a higher chance that their children also will be myopic.

Another factor is that today's children don't get enough sunlight. The sun stimulates a neurotransmitter called dopamine that controls the elongation of the eyes. Eyes growing too long from front to back is a predominant cause of nearsightedness. 

The chances of developing myopia also appears to be influenced by how a person uses their eyes. For example, children who spend long periods of time doing close-up visual work may be more likely to develop nearsightedness.

Early diagnosis and management of nearsightedness is critical. Myopia usually starts in childhood and can worsen year after year until early adulthood. This can lead to high myopia, which may result in other serious eye conditions and even blindness. 

READ MORE about when to have eye exams.

Pediatric eye exams are key in detecting myopia and other vision development issues early. Children should have their first eye exam at 6 months of age. They should have another exam around age 3 and another when they start school. 

Schedule a comprehensive eye exam at the beginning of each school year with an eye doctor near you. Regular exams will help ensure your child is seeing as clearly and comfortably as possible.

Amber Mcmanes also contributed to this article.

Page published on Thursday, January 10, 2019

Medically reviewed on Tuesday, February 8, 2022