Wild bonobos, like humans, experience long-sightedness after they become about 40 years old, shedding new light on the common physiological aging phenomenon among hominidae, Kyoto University research showed Monday.
Age-related long-sightedness, or presbyopia, has been regarded as a unique phenomenon in humans caused by such activities as reading and writing. But the finding indicates senescence of eyes can be commonly seen in primates, according to a paper issued on the online version of the U.S. science magazine Current Biology.
Presbyopia is a decrease in the ability to focus on near visual tasks.
A team from the university's Primate Research Institute conducted the research on grooming by old wild bonobos in Africa, measuring the distance between groomers' eyes and fingers among 14 apes aged 11 to 45 years old.
The study found the grooming distance becomes longer especially after bonobos turn 40, about the same age many humans suffer from presbyopia.
Based on the finding, the team has concluded it is not a result of the modern human lifestyle that demands near visual tasks but of natural aging.
Ryu Heung Jin, a doctoral student on the team, said, "In order to know human evolution, it's important to do research on anthropoids rather than solely analyzing genes."