Allergic Conjunctivitis: This is a common condition in infants, often presenting with puffy eyes due to allergic reactions to environmental factors such as pollen, dust, or pet dander. The reaction leads to inflammation and swelling of the conjunctiva, causing the eye to appear puffy.

Viral Conjunctivitis: Also known as pink eye, this condition is highly contagious and can cause puffiness, redness, and discharge in the eye. It's common in infants and young children.
Blepharitis: Inflammation of the eyelids can cause puffiness, redness, and crusting around the eyes. It can be due to a bacterial or demodex mite infestation.
Blocked Tear Duct: A common condition in infants where the tear duct is blocked, leading to excessive tearing, redness, and puffiness of the eye.

Orbital Cellulitis: A serious infection of the tissues surrounding the eye, which can cause severe puffiness, redness, and pain. It requires immediate medical attention to prevent serious complications.
Retinoblastoma: Although rare, this is the most common primary malignant intraocular tumor in children. It can present with signs such as leukocoria (white pupillary reflex), strabismus, or a red, painful eye, but in some cases, it might cause puffiness due to secondary infection or inflammation.
Neuroblastoma with Orbital Metastasis: A type of cancer that can metastasize to the orbits, causing proptosis (bulging of the eye) and puffiness.

Graves' Disease: An autoimmune disease that can cause the tissues around the eye, including the eyelids, eye socket, and lacrimal gland, to become inflamed and swollen, leading to puffy eyes.
Cavernous Sinus Thrombosis: A rare but potentially life-threatening condition where a blood clot forms in the cavernous sinus, which can lead to symptoms including proptosis, puffiness, and pain in one or both eyes.
Lymphangioma: A rare, benign tumor of the lymphatic vessels that can occur in the orbit, causing proptosis and puffiness of the eye.