My 2 year old son, has swollen eyes with slight watering. the weather is slightly chill and has constant sneezing , running nose?

Allergies: Your son's symptoms are very suspicious for allergies. If this has been going on for more than a few weeks, i would see his pediatrician to discuss what options are out there for relief of symptoms. This includes not only medicine, but cleaning up his environment to try and reduce the exposure to things he might be allergic to. Also, no smoking or other respiratory irritants around the child.