My hamster has redness and swelling around its eyes

Redness and swelling around a hamster’s eyes can be caused by many things, including eye infection, eye parasites, and allergic reactions. For now, keep the hamster’s environment clean—clean the cage, keep water and food clean—and use low-dust bedding.

At the same time, gently clean the eyes with a warm, damp cotton ball, then apply some anti-inflammatory eye drops and ointment, and watch whether the symptoms improve.