The white part of my eye has been red with some inflammation for over a week now. But there is no pain, irritation or swelling of the eye as such. No problems/changes in vision as well. And there seems to be a small white dot on the edge of the iris. I've tried anti allergics and soothing eye drops (on doctor's prescription), the redness has reduced to an extent but it hasn't fully healed yet.  Any ideas what could it be?