The bruised eye of the needle is caused by the blood flowing into the surrounding tissues because the blood vessel was damaged after the blood was drawn and the pressure was not applied in time. If it is within 24-48 hours, you should apply a cold compress to the eye of the needle. You can use ice, surrounded by a towel and put it on the eye of the needle, which can reduce the leakage of blood vessels at this time. It is also possible to use a cold towel, which usually needs to be changed after 5-10 minutes to avoid getting hot. In addition, if the eye of the needle is more than 48 hours, you can use hot compresses, warm hot water bags or hot towels to the affected area for hot compresses, generally 5-10 minutes to change once. You can also apply erythromycin ointment to the wound, which also has a therapeutic effect.