Why is my eye swollen?

Periorbital cellulitis is an infection of your eyelid or the skin around your eyes.  It happens when the soft tissue around your eye and your eyelids get infected

.   person with periorbital cellulitis

Periorbital cellulitis is sometimes called preseptal cellulitis because it happens outside a part of your skull called the orbital septum.   I treat this with 10 day regimen of oral antibiotics.   I also recommend alternating warm and cold compresses to the affected eyelid.  This is just as important as the antibiotic!