What Causes Feeling Of Foreign Particle In Eye?

I feel like there is an eyelash or foreign particule in my eye & it is driving me crazy. I ve used tears to try to flush it out but nothing happens. Can a stye be on the inside of the lid? It only bothers me when I blink or have my eyes closed...so just about all the time. Lol. This is now 24+ hours. Help? Thanks!(go Seahawks!)