Red Eye - Case 4

A 42 year old Australian man presents to your office complaining of a red right (OD) eye with blurry vision.  He says that there is no associated pain or discharge, but it feels like there is something in his right eye.  His visual acuity is 20/50 OD & 20/20 OS.

Case 4

What is the most likely diagnosis?

scleritis
episcleritis
pterygium
pinguecula