Hello, thank you for your question!
Conjunctivitis can be either bacterial, viral or allergic. In the first two cases it is quite contagious, just like a cold. In most cases, conjunctivitis is viral and resolves itself with basic hygiene and non-pharmacological measures:
Cleaning the eyes with a wet wipe, taking care not to share the wipe from eye to eye and with another person
Using moisturizing drops such as Refresh Tears, Systane Ultra or others as often as needed can help improve comfort
With that written, you mention that your child seems to be bothered by light. If your child did not have this symptom before, before the other symptoms appeared, a doctor should be consulted quickly.
I hope this has been helpful to you and if you have any further questions, please do not hesitate to contact me
Tom Samaha, pharmacist