How did my 6month old get impetigo by his eye?

Impetigo: It is primarily caused by staphylococcus aureus, and sometimes by streptococcus pyogenes. Both of these organisms can be present in nasal and oral secretions and easy to get onto the face. The name actually means "school sores" from the latin.

Highly contagious: Impetigo is a highly contagious skin bacterial infection common in preschool children. It is usually spread by direct contact from someone who is infected. It is treatable with topical or oral antibiotics. It most commonly starts near the mouth nose and spreads once the blister-like sore breaks, leaking fluid out. That is how it gets near the eye.