I have dry eyes in the morning. When I go to bed, my eyes feel uncomfortable. I have a scar from an operation 50 years ago to correct a squint. This usually makes me feel like I have something in my eye if I rub my eyes. I have this feeling now if I don't rub my eyes. I have a small lump in the corner of this eye on the outside. It has been there for a few weeks. Could this be a blocked tear duct?