When the unfazed Shiba Inu got stuck in a hedge, we chuckled at his shortsighted shortcut and then moved on with our day. But now we're realizing that shortsightedness isn't funny at all.
According to researchers at the Brien Holden Vision Institute in Sydney, Australia, as many as 1 billion people around the globe could be at risk of blindness in about 35 years, all because myopia (aka shortsightedness or nearsightedness, the common vision problem that makes things far away appear blurry) is spreading like an international epidemic.
By 2050, the researchers estimate that half of the world's population — about 5 billion people — will be nearsighted, and nearly one-fifth of them will be in what's called the "high myopia" category, which puts them at a significantly increased risk of going blind.
Myopia is particularly common in Asia, and it's been on the rise in the United States, as well: 25 percent of Americans were nearsighted in the early 1970s, but by 2004 that number was up to 42 percent, according to the Brien Holden Vision Institute. Myopia currently affects nearly 30 percent of the U.S. population, according to the American Optometric Association.
"[We are] calling on the world — from governments and health agencies, to civil society, parents and schools — to protect the eye health of every child and adult and meet this major public health challenge of our time," says Kovin Naidoo, OD, MPH, PhD, interim CEO of the Brien Holden Vision Institute.
Causes of Myopia
Myopia usually begins in childhood. "The main risk factor for myopia is family history, especially if both parents are myopic," says Lisa Park, MD, assistant residency program director and clinical assistant professor in the department of ophthalmology at the NYU School of Medicine.
And if you're the first child of two myopic parents, better watch out: Firstborns are more likely have myopia, according to an October 2015 study published in JAMA Ophthalmology, supposedly because parents put pressure on the first child to succeed at school. Firstborns spend more time in a "myopiagenic environment" - in other words, studying indoors - than playing outside in natural light like their younger siblings.
But myopia can also develop in adulthood, usually due to environmental visual stress, such as staring at a computer screen for too long, or other health conditions, such as diabetes.
Preventing vs. Treating Myopia
"The main issue regarding myopia is not so much that it should be prevented, but that it should be addressed," explains Dr. Park. "In other words, people who need glasses to correct their myopia should have access to them so that they can see."
Myopia isn't curable or reversible, but treatment options can slow the progression and prevent people from becoming "highly myopic," or at risk of blindness.
Dr. Naidoo suggests that parents encourage their kids to spend at least two hours a day outdoors in natural sunlight, and take them for regular eye exams. "[Parents] should also ensure children don't spend too much time on electronic devices, such as tablets, mobile phones, electronic games, television and other activities which require them to focus close-up for long periods," he adds.
Glasses and contact lenses are the most common treatment for myopia and are proven to slow myopic progression, Naidoo says, but there are other treatment options, including:
- Ortho-K (Orthokeratology), a non-surgical procedure where contact lenses reshape the cornea.
- PRK eye surgery (Photorefractive Keratectomy), where a laser removes a thin layer of tissue from the surface of the cornea, helping to reshape it.
- LASIK, which also uses a laser to permanently change the cornea, but does so by removing tissues from the cornea's inner layers.