During the day, blinking stops in eye that has pain. Symptom or reaction to pain?

[mrl]

Hi - I developed a very sensitive eye several months ago, such that blinking irritates the eye. I've notice that by the early afternoon, that often the left eye lid doesn't fully close when I blink. Has anyone else had this symptom? Initially, I thought it was an unconscious reaction, to avoid the pain from blinking in that eye. However, now I'm wondering if it's possible that this is symptom of a problem. I.e., could the eye be swelling up, or something similar, which prevents full blinking? Just curious. They've tested the pressure in my eye many times, and although it's high normal, it's never abnormal. Thanks. - Mark