From someone else:
Good question, easy answer.
The "cut man" in the corner (if he knows what he is doing) uses first on the boxer's eye what looks like a small metal iron called an "Enswell" It is extremely cold, and they use it to control the immediate hemorrhage so that the swelling is minimized.
Cold is a natural vasoconstrictor; that is, it will make blood vessels constrict or narrow. This process will decrease the amount of blood going into the field of the cut.
Then there are medicines like adrenaline (epinephrine) used in a concentration of 1:1000 used topically to decrease blood flow, and newer agents such as avitene and thrombin.
Surgicel and Gelfoam can also be used .
Sometimes, aspirin can also be utilized to stop swelling.
Usually, this works....if not, the ref calls the fight to save the fighter permanent injury and the audience from looking at all the blood.
* 6 months ago