May 13-19 is Myopia Awareness Week.
The World Council of Optometry and the Brian Holden Visual Institute started this campaign in 2019 to encourage caregivers to protect children's eyesight by highlighting myopia and its treatment. Myopia is now considered the largest eye threat of the 21st century.
What is myopia?
Myopia otherwise known as nearsightedness is an eye disease where distant light focuses in front of the retina instead of on it. Far items appear hazy, whereas close ones appear clear. Most commonly, the problem results when the eyeball grows too long.
Myopia usually starts between ages 6 and 14. Approximately 5% of preschoolers, 9% of school-aged children, and 30% of teenagers have it. Children of nearsighted parents are more likely to develop myopia. The prevalence of myopia in the United States has increased from 25% in the early 1970s to nearly 42% by 2004. The cause is unknown, but many think it's due to increased time indoors spent using computers and playing video games.
The technical definition of myopia is having a negative refractive error, measured in diopters. A diopter (D) is a unit of measurement used to quantify the optical power of a lens or the refractive error of an eye. A diopter indicates how much light is bent or refracted by a lens. Positive diopters indicate converging lenses (used for farsightedness), while negative diopters indicate diverging lenses (used for nearsightedness). Myopia is usually diagnosed when the refractive error is greater than or equal to -0.50 diopters. High myopia, also called pathologic myopia, is generally defined as near-sightedness of -6.00 diopters or greater. High myopia is linked to a markedly higher risk of cataracts, open-angle glaucoma, and retinal degeneration and detachment. There is a considerable lifelong risk of serious visual impairment, including blindness, from these disorders.
Some History of Myopia
Myopia was initially described by the Greek philosopher and polymath Aristotle in 350 B.C. He coined the Greek term "muoops" from "muein" (to close) and "oops" (the eye) and noted the association of frequent blinking, squeezing of the eyelids, and close reading.
Nicholas Cusanus, a German cardinal of the Roman Catholic Church, made the first eyeglasses for myopia, in 1451. The German astronomer and mathematician Johannes Kepler proved that incoming light focused in front of the retina caused myopia in his Clarification of Ophthalmic Dioptrics and demonstrated that concave lenses could correct myopia. A myopic eye was investigated by a Dutch professor of medicine, Vopiscus Fortunatus Plempius, in 1632 and found to have a lengthened axial diameter.
Jan Purkinje, a Czech anatomist and physiologist, was myopic and tried to correct his vision based on something he read. He was instructed to use a bag of iron filings that would help him see due to its magnetic power. However, Purkinje thought it was the weight of the bag that made this procedure work. He found that he could read less but saw better far away in the morning after putting a leather pouch with a 1/2-pound weight over his eye at night.
Current and future prevalence of myopia
Almost half the world’s population will be myopic by the year 2050, with nearly one billion people in the high myopia category. It is the most common eye disorder, affecting 1.5 billion individuals, 22% of the world’s population, and is a common cause of vision impairment. Its prevalence has risen dramatically since 1950.
Below is a graph showing the number of people estimated to have myopia and high myopia for each decade from 2000 through 2050. Error bars represent the 95% confidence intervals
Treatment
Myopia in children and adults is treated with glasses or contact lenses. Refractive surgery, such as Lasik, is mainly reserved for adults.
Control
There are four potential alternatives to glasses or contacts that have the goal of restoring eyesight and preventing the eye from elongating as the child grows older. These alternatives, without any specific ranking — low-dose atropine drops, MiSight contact lenses (soft contact lenses with different designs for the central and peripheral parts), multifocal contact lenses, and orthokeratology (a non-surgical procedure that uses contact lenses to temporarily reshape the cornea and correct vision) — have the potential to significantly contribute to the long-term preservation of a child's eyesight.
Prevention
Ian Morgan, a myopia researcher at the Australian National University, discovered that spending more time outdoors can prevent myopia development. A two-year study involving over 4,000 six and twelve-year-old children in Sydney found that children who reported spending more time outdoors were less likely to be myopic. Pei-Chang Wu, an ophthalmologist in Taiwan, was inspired by Morgan's research and convinced Taiwan's Ministry of Education to encourage all primary schools to send students outdoors for at least 2 hours a day, every day. The prevalence of myopia among Taiwan's elementary school students began falling from 50% in 2011 to 45.1% by 2015. Other studies have found that outdoor time can reduce the chances of kids developing myopia even if they are doing near work or have parents with myopia.
COVID-19 has affected the prevalence of myopia. A study of school-aged children in China after five months of COVID-19 home confinement revealed a substantial decline in visual acuity among 123,535 elementary school children following school closures. The lack of outdoor time is considered a likely explanation.
Prevention is Key
Prevention of myopia is superior to control or treatment from both a societal and individual standpoint.
Long-term Health
Myopia can lead to cataracts, glaucoma, and retinal detachment. Prevention would reduce the risk of these complications.
Economic Burden
Prevention is significantly more cost-effective than control or treatment. The expenses associated with providing glasses, contact lenses, or undergoing corrective surgeries over a lifetime are substantial. Additionally, the indirect costs such as reduced productivity due to impaired vision can be staggering.
Quality of Life
Myopia can have profound effects on one's quality of life, impacting activities like driving, reading, and even social interactions. Prevention not only avoids these limitations but also preserves the natural state of vision, enhancing overall well-being.
Myopia can hinder academic performance and limit career opportunities. Preventing its onset ensures that individuals have the best chance to excel academically and pursue their desired professions without vision-related obstacles.
Living with myopia can cause psychological distress, affecting self-esteem and confidence, especially in children and adolescents. Prevention promotes positive self-perception and eliminates the need for ongoing management, reducing the psychological burden associated with vision impairment.
The Future of Myopia Research
Myopia has to be acknowledged as a significant public health issue. Further research on prevention is urgently needed to preserve individual well-being, educational opportunities, and ocular health while also saving society significant financial resources.