Puffiness of one
eye is usually due to a localized cause like
infection, abrasion of cornea, foreign body in
eye, maxillary sinusitis of same side, lacrimal gland infection, infection of hair follicle of the eye lid etc. Consult an eye specialist soon.
For a detailed list you can check out this link: http://en.diagnosispro.com/differential_diagnosis-for/unilateral-puffy-eyelid-edema/35765-154.html
Hope this helps. Please let me know if there is any thing else and do keep me posted. Take care!