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 condition is complex and is generally associated with bacterial infections, refractive errors, poor hygiene habits and weak body resistance.