Wimpern sind so konzipiert, dass sie Flüssigkeit ausstoßen und eine klare Sicht bewahren. Sie bestehen aus einer hydrophoben, gebogenen und flexiblen Faseranordnung mit Mikroratschen an der Oberfläche und einer Makrokrümmung, die der Brachistochrone-Kurve ähnelt, wodurch sie einströmende Flüssigkeit schnell und gezielt ausstoßen können

>The hydrodynamic advantages of eyelashes, particularly their ability to expel unwanted liquids from the eye to maintain visual clarity, have received little attention. For instance, during facial washing or intense physical activity, the eyes are exposed to significant amounts of water or sweat without compromising clear vision.

>Based on their findings, the researchers revealed the control mechanism governing transfer direction and contact time, which arise from the multi-scale asymmetric structures and heterogeneous elastic deformations of the fiber array. They also developed a quantitative computational model to calculate the elastic forces acting on the fiber array.
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>This research has also led to the design of eyelash-mimetic rapid liquid transfer edges, including aesthetically pleasing and protective false eyelashes, waterproof imaging devices, and ventilated structures.

Paper: [Rapid water drainage on human eyelashes of a hydrophobic Brachistochrone fiber array | Science Advances](https://www.science.org/doi/10.1126/sciadv.adr2135)

How these dynamics change across different eye types around the world?