Based on the description shared by you the common possibilities are corneal abrasions, corneal infections, conjunctivitis, blepharitis, any foreign body in the eye
. These all can cause a sore eye
and watering from the eyes. Conjunctivitis due to allergies or infections either viral or bacterial is the commonest cause of red sore eyes, itchiness and discharge. It is best to get your eyes checked by an ophthalmologist and only after a correct diagnosis treatment can be started.