Khaberni - Scientists have long believed that the increased use of screens, especially among children and young people, is primarily responsible for the rising rates of myopia worldwide.
However, a new study from the College of Optometry at the State University of New York suggests that the issue is more complex, and that the problem may lie in a simple daily visual behavior practiced indoors.
In the study published in the journal "Cell Reports", the researchers explain that myopia may not be caused by screens themselves, but rather by the continuous focus on close objects in enclosed spaces with dim lighting, which greatly limits the amount of light reaching the retina.
Dr. José Manuel Alonso, the principal supervisor of the study, says that myopia has reached epidemic levels globally without fully understanding its causes, indicating that the new findings clarify that the amount of light reaching the retina during ongoing close work, especially indoors, may be the most important common factor.
Myopia is a visual disorder that causes blurred vision for distant objects. While genetic factors play an important role, the rapid spread over just a few generations confirms that environmental factors are equally important.
The researcher Urusha Maharjan, who led the study, explains that in bright daylight, the pupil naturally constricts to protect the eye while allowing enough light to enter, but when we focus on close objects indoors, whether phones or books, the pupil also constricts but not because of the brightness of the light, rather to enhance image clarity, and in enclosed spaces with dim lighting, this combination significantly reduces the light reaching the retina.
According to the mechanism discovered by the researchers, myopia develops when the retina does not receive sufficient stimuli due to the surrounding poor lighting and the excessive pupil constriction resulting from focusing on close distances.
In contrast, myopia does not develop when the eye is exposed to bright light, where the brightness of the light controls the constriction of the pupil instead of the distance of vision. The team also found that excessive pupil constriction worsens the longer periods of focusing on close objects, and it increases more when the eye already suffers from myopia.
The study also shows that there are other factors associated with myopia such as eye movement disorders during accommodation and the effect of blinking on pupil constriction. If this mechanism is proven, it may lead us to a new understanding of dealing with myopia, where it can be controlled by exposing the eye to bright light with reduced pupil constriction caused by close focusing, whether by using multifocal lenses that reduce the strength of accommodation required, or by atropine drops that prevent pupil muscle constriction, or simply by spending time outdoors and looking at distant spaces without the need for accommodation.
And the study warns that any treatment method will fail if the person continues to focus for prolonged periods on close distances indoors under dim lighting.
