There are several ways to reduce the swelling of one eye: 1, if the swelling is caused by trauma, local hot compress for 30 minutes, repeat 3-5 times to promote local blood circulation, accelerate the flow of blood can reduce swelling, thus achieving the role of swelling. 2, if the swelling is caused by allergies, can be treated with topical anti-allergy drugs, such as levocetirizine hydrochloride or loratadine citrate tablets, etc., can relieve the symptoms of allergies. 3. If the swelling is caused by mosquito bites, you need to rinse it repeatedly with soapy water, you can apply aloe vera gel externally or scrub with glycolic acid lotion, you can apply ice packs for 10 minutes each time, 3-5 times a day, and if the itching is very serious, you can take oral antihistamines for further treatment.