I Am An Asian Woman Of 29 Yrs Old, Lives

I am an Asian woman of 29 yrs old, lives in New Zealand for 5 months. I have a blister on the sclera close to iris of my right eye. it happened before a week and at the beginning it was red and itchy. then i got an allergy eye drop and an eye ointment from a doctor. i used them for 3 days. now red and itchiness is gone away. but the blister appears. Is this serious issue? please give me a quick answer.