red and teary eyes, also sensitive to light.

I started wearing contacts 3 years ago but i stopped because f the damage it did to my eye. This year, after having stopped wearing them for a whole year, i wore them a few times. I don't know if my problem has anything to do with contacts but my eyes, mainly the right, have gotten really red. My eyes are usually very watery but now they are extra teary and extremely sensible to light. This sometimes brings headaches, but very minor ones. What do I have?