The causes of unilateral lower eyelid itchiness and puffiness are as follows.
First consider allergies, such as allergic conjunctivitis, an inflammation caused by a hypersensitivity reaction of the eye tissue to an allergen.
If combined with redness and pain, consider an inflammatory infection, such as blepharitis.
The etiology of this disease is complex and is generally related to bacterial infection, refractive error, poor hygiene habits, and weak body resistance.