It feels like there is something in my eye. wtf?

It's been bothering me since yesterday morning, feels like there's something under my lower eyelid in the inside corner scraping. Dx I went to see the opthalmologist today, and he looked around in there, put a dye in to check for abrasions and put an anaesthetic in and still couldn't see anything wrong. He left as frustrated as I was and all I have now is some artificial tears. X_x Does anyone have some suggestions? Has this ever happened to anyone? I'm just worried that it's all in my head or something... ):