We have spent our entire lives blaming spring for our tiredness. Science has just shown that we have lived deceived

March is coming, the days are getting longer, temperatures rise and suddenly our body begins to fill with a feeling tiredapathy and drowsiness that takes over us. Traditionally, this is considered ‘spring astheniaand people, logically, do not stop searching for their symptoms on the Internet and buying expensive vitamin complexes to compensate for the bad feeling that the change of season leaves. But… What is true in all this? A paradigm shift. Until recently, evidence on this phenomenon was scarce and contradictory; however, a key investigation published in the Journal of Sleep Research has recently come to shed light on the matter. The research, led by Dr. Christine Blume from the Center for Chronobiology at the Psychiatric University Hospital of Basel, followed 418 adults from Germany, Switzerland and Austria for more than a year, from April 2024 to September 2025. Every six weeks, participants answered questionnaires about fatigue, drowsiness, insomnia and sleep quality, and at the end of the research they only had to cross-check information to determine if there really was any interfering pattern. with our health. The results. Here what was seen is that a resounding 47% of the participants claimed to suffer from “spring asthenia”, but the reality is that when the information was cross-checked there was absolutely no seasonal or monthly variation in the levels of fatigue, daytime sleepiness or quality of sleep. And statistically the tiredness that people feel in spring is statistically identical to what they feel in autumn or winter. In fact, fatigue in daily activities tended to decrease slightly as the days had more daylight hours, without any specific “peak” of fatigue being recorded during the spring. In this way, the conclusion drawn is that the discrepancy between what people think they feel and what objective data shows suggests that we are dealing with a cultural phenomenon and not a genuine seasonal syndrome. Why do we believe it? This is where the study gets genuinely interesting, since the authors do not simply deny the phenomenon, but rather propose a psychological explanation for why we experience it so convincingly. Nocebo effect: if we expect to be tired in spring, we interpret any sign of fatigue as confirmation of what we thought was going to happen. Cognitive dissonance: good weather generates high social pressure to enjoy it with outdoor activities. The problem is that when the energy does not appear, saying that you have ‘spring asthenia’ is a good excuse to not feel guilty for not following the group. Labeling effect: Like wine tasting better when we’re told it’s expensive, knowing that “you get tired in spring” actively changes how we interpret our own physical sensations. What chronobiology says. It is a reality that we are not robots and that our body reacts to the environment, and this is where chronobiology confirms that there are seasonal variations in sleep linked to the number of hours of daylight we enjoy. Studies in pre-industrial populations in Tanzania, Namibia or Bolivia show that in winter they sleep approximately one hour more than in summer. Likewise, recent research on university students in Seattle confirms that exposure to daylight is vital for our circadian rhythm, however, none of these physiological changes translate into a “clinical picture” or a peak in fatigue in spring. In medicine. Nowadays, when you go to your primary care doctor, it is impossible to receive treatment for ‘spring asthenia’ because it is not included in any official classification. However, doctors warn that a patient who arrives with great fatigue for consultation should not be sent away, even though he relates it to the arrival of spring. It must be remembered that there are many diseases that can cause this condition, such as anemia, a severe allergy, an infection or even thyroid disorders, among others. A lucrative business. While science dismisses the existence of ‘spring asthenia’, the reality is that people’s sensation is the perfect breeding ground for private clinics and dietary supplement brands. When we feel bad, we want a quick solution with a pill, and this makes the sale of multivitamin complexes, caffeine pills and a host of products related to reducing fatigue increase their sales. Images | Vitaly Gariev Arno Smit In Xataka | Only one in four Spaniards has rested on vacation. The culprits: work anxiety and the inability to disconnect

We have been blaming mobile phones for myopia for years. Now we have a much more subtle suspect: lack of light

It is quite a grandmother’s and mother’s phrase to hear that spending a long time in front of a screen or being very close to a book can cause us to develop a disease in the eyes like the myopia. However, science has long suspected that “close work” alone does not explain why myopia has become a global pandemic. The new. Now a revealing study has proposed a physiological mechanism that fits all the pieces of the puzzle together, placing the blame not only on what we look at, but on the amount of light that reaches the back of our eye while we do so. And the investigation is quite justified, since the data is scary. In Spain, 19% of children between 5 and 7 years old are already myopicand projections estimate that by 2050 half of the world’s population will need glasses. To stop this, we need to understand exactly the mechanism that produces myopia, and a team from New York has found the key. The famine of light. The work, recently published in the prestigious magazine Cell Reports by researchers, points to a fascinating concept in this case: the light deprivation hypothesis. Until now we knew that focusing on nearby objects is closely linked to the development of myopia. But what this study has measured with empirical precision is how the myopic eye reacts to the healthy eye during this process. What they have seen. The main finding is that myopes suffer from excessive accommodative pupillary constrictionthat is, when you look closely, the pupil becomes much smaller than normal. If we add to this that close-up work is usually done indoors where lighting rarely exceeds 500 lux, compared to 10,000 lux outdoors, the result is a lethal cocktail for the eye: the combination of dim light and a maximally contracted pupil causes the retina to “starve” due to lack of light. The short circuit. Here the question that logically must be asked is: Why does this lack of light cause the eye to grow abnormally, causing myopia? This is where the purest neuroscience comes in, since our retina processes the image through two main channels: the ON path that is activated with increases in light, and the OFF path, which reacts to shadows. In previous work from 2024, this same team had already shown that in myopic patients the ON pathways have serious deficits, since they are less sensitive and slower. Now the new hypothesis postulates a vicious circle in which, when reading or looking at a cell phone indoors, the pupil closes too much. And this is a problem, since chronic lack of light further weakens the retinal ON pathway, and this imbalance sends erroneous signals that ultimately promote elongation of the eyeball. The treatments. This proposal not only stands out for explaining the biological mechanism of myopia, but also unifies at once why the treatments that ophthalmologists They have been applying it empirically for years. One of the examples is spending time outdoors, but not because it cures, but because the sunlight is so intense that it more than compensates for having a small pupil, keeping the ON pathway stimulated and slowing the progression of myopia. Another example is the use of atropine drops in children to stop myopia thanks to the dilation of the pupil so that more light enters the retina. The same goes for multifocal lenses that are used to reduce accommodation effort, since the pupil does not need to constrict as excessively. It is not definitive. As is almost always the case in science, this work does not demonstrate a direct coincidence yet, but rather offers us an incredibly solid and plausible physiological mechanism supported by very robust data on the behavior of our pupil and neural pathways. But there is still a way to go with new long-term studies to confirm the hypothesis 100%. While we wait for those results, the practical conclusion seems clearer than ever: the problem is not just the tablet or the book. The problem is doing it in the dark, so if you are going to strain your eyes up close, make sure you turn on a good lamp and, above all, don’t forget to go out into the sun. Images | Akshit Dhasmana In Xataka | Denialism has reached one of the last corners of science still free of it: seeing glasses

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