Eye pain, redness and swelling may be caused by mosquito bites, granuloma, glaucoma and so on. 1. Mosquito bites: more mosquitoes outside in summer, outdoor activities, may be mosquito bites eye, resulting in local inflammation, causing eye redness, swelling and pain. 2. Granuloma: bacterial infection, most commonly caused by Staphylococcus aureus, can be caused by sharing eye cosmetics with others, manifested as small lumps on the surface of the eyelid or the inner side of the eyelid, which can also lead to eyelid congestion and swelling. 3. Glaucoma: It is a pathologic elevation of intraocular pressure, manifested by redness of the eyes, pain in or around the eyes, headache and dizziness, and loss of vision. Eye pain, redness and swelling may also have other causes, it is recommended to go to the hospital in time, improve the examination to clarify the cause of the disease, and then give targeted treatment or treatment.