Lately I've experience some sort of buildup on my left eye only. During the early morning (3 - 4 AM) I suddenly get a burning sensation in the left eye and it feels like there is something rubbing against my eye. I immediately remove the CPAP mask and try using a tissue to whip it away, but there is nothing there. I can feel something between the eye and the eye lid that seems to be moving around. I apply itchy-eye eye drops to get it out and provide some relief for the burning sensation, but that only gives relief for a few minutes. After about 30 minutes or so the object has completely dissolved and the burning is gone. I think part of the problem may be air leakage around the nose.