Why Short-Sightedness Cases Are Increasing Rapidly Around The World
Myopia is the term used to describe what is more commonly referred to as short/near-sightedness. Cases of Myopia are increasing rapidly around the world, and a new study is trying to explain why.
Researchers from the State University of New York (SUNY) College of Optometry, stated that while our modern tendency to spend more time indoors is definitely a contributor, increased screen time is not the only driver in this unusual increase.
The team, according to Science Alert, ran lab tests on 34 volunteers, 21 who have myopia, and 13 with standard vision. The participants were given square targets that varied in brightness and contrast to focus on multiple times, one eye at a time.
Eye behavior that was recorded in patients with myopia showed that activities and tasks that require close-up viewing could be contributing to their short-sightedness due to the way the pupil constricts to limit how much light enters the eye.
“Myopia has reached near- epidemic levels worldwide, yet we still don’t fully understand why,” said visual neuroscientist Jose-Manuel Alonso.
“Our findings suggest that a common underlying factor may be how much light reaches the retina during sustained near work – particularly indoors.”
The reports show that the researchers wanted to look at three specific behaviors associated with looking at nearby objects: how the eyes focus, how they turn inward, and how the pupils constrict. They made adjustments to accommodate for the ON/OFF pathways in the retina, which is responsible for processing light and darkness.
Weaker ON pathways have been connected to myopia but the underlying mechanism hasn’t been completely clear, the researchers stated. They also found that contrast matters more than brightness when it comes to the eyes turning inwards and the pupils shrinking.
“In bright outdoor light, the pupil constricts to protect the eye while still allowing ample light to reach the retina,” said optometry doctoral student Urusha Maharjan.
“When people focus on close objects indoors, such as phones, tablets, or books, the pupil can also constrict, not because of brightness, but to sharpen the image. In dim lighting, this combination may significantly reduce retinal illumination.”
So one of the biggest arguments now being made is that blurry vision is not the only factor that triggers or worsens myopia, but also a lack of light, which could help explain why corrective lenses that are too strong can actually hinder an individual with myopia.
“Our results support the hypothesis that myopia develops in children with poor retinal stimulation,” the researchers report.
This study is just one step in reaching an actual solid conclusion, as it utilized a small sample of people whose eyesight wasn’t measured over time or compared in outdoor versus indoor conditions.
“This is not a final answer. It’s a hypothesis grounded in measurable physiology that brings together many pieces of existing evidence,” Alonso said.
“More research is needed, but it gives us a new way to think about prevention and treatment.”
The research was published in Cell Reports.
Eric Mastrota is a Contributing Editor at The National Digest based in New York. A graduate of SUNY New Paltz, he reports on world news, culture, and lifestyle. You can reach him at eric.mastrota@thenationaldigest.com.