It is probobly a stye. Use a warm, wet washcloth or something similar and apply pressure on the area. Pulling the eyelids on the eye works too. I had two styes in the past. One lasted for about a...
It could be either a sebaceous gland or a lymph node.
Sebaceous gland... that's an oil gland that has become plugged, and because it continues to produce oil (sebum) it gradually swells and...