1) Eyebrows protect the eyes from moisture, which temporarily impairs vision and can also act as an irritant. Sweat can drain from the forehead at high ambient temperatures or during increased physical activity. Sweat contains sulphate compounds, calcium salts, ammonia, etc. Eyebrows prevent sweat from getting into the eyes, which is an irritant to vision.
The hairs on the eyebrow area have a special growth pattern: they usually do not adhere tightly to the skin, the direction of hair growth at each eyebrow goes up at the beginning, and towards the temples at the end. So, they are a natural barrier to moisture: drops to a greater extent flow down the bridge of the nose or along the temples.
By the same principle, eyebrows protect the eyes in the rain.
As a result of evolution, man practically got rid of vegetation on his body, but his eyebrows and eyelashes were preserved on his face. If there were no eyebrows, then there would still have to be some obstacle along their line, for example, very long and thick eyelashes, folds of skin or a protruding frontal bone. But these are just the assumptions of scientists.
2) A person's eyebrows are involved in the expression of surprise, joy, censure, anger, contempt, etc. Usually, eyebrow movements occur unconsciously, but at the same time are under the control of a person, for example, an actor actively uses facial expressions during a game to depict feelings and emotions, in incl. and eyebrows.
3) The eyebrows of each person are unique, while they are actively involved in memorizing or recognizing a person. The main differences between eyebrows are: shape, thickness, length, rise, color.
Interesting are the results of a test conducted to find out the degree of influence of eyebrows on personality identification. During the experiment, the respondents were asked to recognize the face of a famous person, which was missing either eyebrows or eyes.
The results suggest that the eyebrows play a greater role in personality identification than the eyes.
Both in the 21st century and in ancient times, the eyebrows of women and men differed from each other. The woman is characterized by more refined facial features. In recent years, eyebrows have become one of the objects of beauty. Women are more likely to groom their eyebrows, believing that attractive eyebrows make the face more beautiful. Men generally confine themselves to trimming and combing their eyebrows, or do nothing at all.
The natural shape of eyebrows is often artificially changed, for this purpose the following tools are often used: eyebrow tweezers, eyebrow brush, nail scissors, eyebrow pencil, eyebrow powder, eyebrow dye, permanent eyebrow makeup.
4) Eyebrows also play an aesthetic function; makeup is also applied to them using rhinestones, etc. An eyebrow piercing or a tattoo in the superciliary area of the face is used as a decoration.