In fact, astronauts, of course, also cry. However, as explained NASA, in microgravity, the tears do not flow down, how on Earth and remain in place. They gather around the eyeball.

Moreover, these tears cause a lot of discomfort.

In may 2011 astronaut Andrew Feustel possibly first learned what happens when watering eyes in space.

During the spacewalk, Feustel felt a strong burning sensation in the eye. As it turned out later, inside the helmet of astronaut got a little money from fogging, which caused tears. He was able to RUB the eyes of sponge-like device, which is usually used for holding his nose when the pressure compensation, and to alleviate their state.

According to scientific explanation, tears should not cause pain. Although we do not know exactly why we cry, the tears have a mitigating effect. But as you know, weightlessness affects the person's vision, which is caused by the displacement of the liquid to the head. It is also possible that in space there is a dry eyes, and a sudden liquids can cause burning.

As explained another astronaut Ron Parise, if going to a lot of tears, they come out of the eyes and swim around. In other words, you can enjoy watching before you pass your weightless tears.
Weightlessness

What is the state of weightlessness? We are accustomed to think that the astronauts in space swim, contrary to the laws of gravity. Because many believe that in space there's no gravity. Actually gravity exists everywhere in the Universe and it is the most important force that affect all existing in space.

What happens with a cosmonaut, is a weightlessness? More precisely, this state can be called a free fall.

Why astronauts not fall to the Ground? Here there is a law of free fall acceleration. If the astronaut dropped the Apple on the space station, all they will fall: and Apple, and the astronaut, and the station. Only they are not fall on the Ground and around it, as they speed relative to the Earth. Objects on the earth's orbit appear to be floating, but actually they move with the same orbital velocity, and the spacecraft, more than 28 000 km per hour.
The liquid in weightlessness

Experiments with water in weightlessness on the International space station.

Drink water in space - is also not an easy task. As the water follows in microgravity, all liquid containers drink through a straw. Without it, the astronauts would have "off" small pieces bubble floating water.

As the astronauts go to the toilet? Water, for obvious reasons, cannot be used to drain. Waste products are sucked into the special funnel with a hose, and then thrown into the open space.