50 Percent Of The World Will Suffer From Nearsightedness By 2050, Says Study
We might have more people suffer from nearsightedness in the near future, claims a shocking new study. Researchers estimate that half of the world’s population are expected to suffer from this visual impairment by the year 2050.?
The reason? Natural selection among humans.?
In case you didn’t know, natural selection is a process where human species adapt and introduce traits to help the species survive for longer and thrive.
Professor Jianzhi Zhang from the University of Michigan along with his colleague Erping Long looked at genetic and medical data of 63,185 individuals from the age group of 40 to 69. The main motive of this research was to identify the genetic and environmental factors that contribute to the development of a disease.
Looking at the data, researchers discovered that the prevalence of myopia (nearsightedness) increased from 24.4 percent to a whopping 41 percent between people born between 1940-44 and 1965-69.
After correlating with the effects of age on eyesight, researchers discovered that the occurrence of myopia at the age of 40 has increased from 30.3 percent to 43.5 percent in the 25 year time period.
Researchers revealed that nearsightedness in individuals is linked with worse reproductive success, which basically indicates that natural selection is acting against myopia since it wants its species to survive.?
However, researchers also discovered that nearly half of the genes that are connected with an increased risk of myopia which is visible more commonly among the population has also been associated with better reproductive success.
Eight genes were linked with people giving birth to their child at a lower age whereas five variants showed present in people who have more children overall. Researchers haven’t been able to find a causal link between this yet.?
However, Professor Zhang believes that chances are myopia-associated mutation occurs next to a reproduction-associated mutation in the human genome, where myopia-associated mutation actually walks with the reproduction-associated mutation, but actually only the latter has been picked by natural selection.
Researchers said in their study, “Our finding does not alter the prevailing view about the importance of environmental factors in the myopia epidemic. Nonetheless, based on the UK population of 55,429,643 in 1969, the positive selection adds 116,957 myopia cases per generation in the UK alone, indicating that the selection has a substantial impact.”