I just noticed a very tiny bump under my left eye lid. No pain, no protrusion. But my eyes are dry and irritable. What could this be? Who should I see

Blocked gland. You could have blockage in one of the many tiny glands in our eyelids that produce mucus. If it concerns you or if it gets bigger or becomes painful, you should see an ophthalmologist.
Chalazion. Try a warm wash clothe to the bump three to four times per day. If this does not work, visit an ophthalmologist.