Why Everyone Seems to Need Glasses Now
▼ Summary
– A new study suggests the global rise in nearsightedness (myopia) is not solely caused by phone use, but by a combination of factors.
– Researchers propose that prolonged focus on close objects in dim indoor lighting may strain the retina and contribute to myopia.
– In dim light, the pupil constricts both to sharpen close-up images and due to low brightness, which can reduce retinal illumination.
– Bright outdoor light causes the pupil to constrict primarily in response to light, which helps maintain healthy retinal stimulation.
– This theory is a testable hypothesis that reframes the interaction of visual habits and lighting, but it requires further confirmation.
It seems like more people than ever are reaching for a pair of glasses, a trend often blamed squarely on our collective addiction to smartphones. However, new research indicates that the story behind the global rise in nearsightedness is more nuanced, pointing to a combination of factors beyond just screen time.
Scientists from the SUNY College of Optometry have identified a potential new culprit: spending too much time focusing on close-up objects in dim indoor lighting. Their study, published in the journal Cell Reports, proposes that this specific combination places a unique strain on the eyes, contributing to the development of myopia, or nearsightedness. This condition, where the eyeball elongates slightly making distant objects appear blurry, is projected to affect half the world’s population by 2050.
While excessive phone use has been a primary suspect, the research suggests the environment in which we use these devices is critically important. The issue arises from how our pupils behave. In bright outdoor light, the pupil naturally constricts to protect the eye while still letting in sufficient light. When we focus on something up close, like a phone or book, the pupil also constricts to help sharpen the image, regardless of the ambient brightness.
The problem occurs when we perform this close-focus work in poorly lit rooms. In dim lighting, this dual mechanism, constricting for both focus and in a weak attempt to manage low light, can drastically reduce the amount of light actually reaching the retina. For individuals who are already nearsighted, this effect is even more pronounced.
The researchers’ hypothesis is that prolonged periods of close visual work in dark settings may deprive the retina of the healthy stimulation it needs, potentially encouraging the eye to elongate and myopia to develop. In contrast, working in a brightly lit environment causes the pupil to constrict primarily in response to the light level, which maintains better retinal illumination and is less stressful for the eye.
It is crucial to note that this theory is still speculative and requires more testing to confirm. “This is not a final answer,” said study co-author Jose-Manuel Alonso, a professor at SUNY. “But the study offers a testable hypothesis that reframes how visual habits, lighting, and eye focusing interact.” If validated, these findings could lead to new, simple recommendations for preventing myopia, such as ensuring adequate lighting during reading or screen use. The key takeaway is that it may not be the screen itself, but the dark room we often stare at it in, that’s part of the problem.
(Source: Gizmodo)