Nasolacrimal Duct Obstruction (NLDO): This condition is common in infants and can cause a green or yellow eye discharge due to the accumulation of bacteria in the tears. The blockage prevents the normal drainage of tears, leading to infection and discharge.

Conjunctivitis: This can be caused by bacteria (such as Gonococcus or Chlamydia), viruses, or allergens. Bacterial conjunctivitis often presents with a purulent discharge that can be green or yellow.
Blepharitis: Inflammation of the eyelids can cause discharge and may be associated with conditions like seborrheic dermatitis or rosacea in infants.
Keratoconjunctivitis: Inflammation of the cornea and conjunctiva can be caused by various factors, including infection, and may present with discharge.

Gonococcal Conjunctivitis: Although less common, this condition is serious and can lead to corneal perforation and blindness if not treated promptly. It is particularly concerning in newborns who may have acquired the infection from their mother during birth.
Chlamydial Conjunctivitis: Similar to gonococcal conjunctivitis, chlamydial infection can have serious consequences if not treated, including the development of pneumonia.
Herpes Simplex Virus (HSV) Keratoconjunctivitis: HSV infection can cause severe ocular and systemic disease in infants, making prompt diagnosis and treatment crucial.

Leukocoria-associated Conditions: Although not typically presenting with discharge, conditions like retinoblastoma can cause a white pupillary reflex and should be considered in the differential diagnosis of any infant with unusual eye symptoms.
Congenital Glaucoma: This condition can cause tearing, redness, and discharge due to increased intraocular pressure, though it is less common and the discharge may not typically be described as green or yellow.