Have you ever imagined what are the eyelashes exactly for? Or which is the ideal lashes—those longer prettier eye lashes or the smaller one?
Well, a new study has found that the eye lashes have an important role to play. They protect our eyes from dust and damages. But it’s not the ‘standing out’ long lashes that are considered to be ideal by the scientists, but those lashes having a length about one-third the width of the eye length are said to be the best one that serve the main purpose of protection of these vision imparting organs.
According to the researchers, eyelashes with the said length were only found offering an ideal protective zone of still air over the surface of the eyeball.
Study lead author Dr David Hu says questioning the eyelashes’ function first came in his mind while he was gazing into the eyes of his newborn daughter.
Hu, a Georgia Institute of Technology associate professor of biology and mechanical engineering, says, “For a long time there were quite a few hypotheses about what eyelashes were for…But there’s been no careful study of how they would do these things.”
The researchers studied the length of eyelash in 22 mammals, including the African elephant, camel, chimpanzees, giraffe, red kangaroo and zebra, in order to explore more about this body part.
“We visited New York’s Museum of Natural History to observe the eyelash length of hundreds of these animals,” he said while adding, “We found that they followed the pretty strict relationship, i.e. the lash is about one-third the width of the eye.”
In order to establish their hypothesis in greater detail, the researchers created a fake eye to examine its function in a walking-speed wind tunnel by switching different lengths of mesh eyelash. The researchers recorded the measurement of the changes in evaporation from the surface of the fake eye.
“The surprising thing observed was that there was an optimum eyelash length, and that means that of all the eyelashes out there, that there’s a particular one that lower the flow of air on the eye’s surface,” Hu said.
According to the researchers, minimising the air flow at the eye’s surface lowers evaporation and cuts the amount of dust and harmful fine particles coming into contact with the eye.
The findings of the study were published in the Journal of the Royal Society Interface.