Son has allergies or allergic reaction to something ?

This is my son his eye is swollen from the inside it looks like it and i don’t know what it causing it i think he might have allergies but i’m not sure i know it’s not pink eye. his eye was fine all day today he started rubbing his eyes when we got home and his eye just got so swollen. all the stores around me it’s closed so i have to wait for the morning so for now i’m just using a few hot rags for his eye until i can pick up allergy eye drops or benadryl or does this look like he is allergic to something ? i just don’t know what i don’t have any pets and this never happened before only recently it been happening