If a bug enters the eye and causes redness or swelling, it is necessary to rinse the eye with water to flush out the bug, and then go to the ophthalmology department of a hospital, where the doctor will determine whether an infection or an allergy is occurring, and then administer the appropriate medication. Bugs can irritate the eyes after entering the eyes, either because the bacteria carried by the bugs have infected the eyes causing redness and swelling, or because the toxins secreted by the bugs themselves have caused an allergic reaction in the eyes causing redness and swelling. The patient needs to rinse the eye with water first to flush out the bugs and avoid further damage, and then go to the ophthalmology department of the hospital in time for the doctor to determine whether it is caused by infection or allergy. If the infection is caused by infection, you can order antibiotic eye drops for treatment, such as ofloxacin eye drops, tobramycin eye drops, etc.; if the allergy is caused by allergy, you can order anti-allergy eye drops for treatment, such as olopatadine hydrochloride eye drops, azelastine hydrochloride eye drops, etc.. Specific medication should be carried out under the guidance of a doctor.