My joints (knees and elbows) hurt and at the same time my eyes have blurry vision and headaches. my doctors/opthamologists don't know what it is. it has been 2 years since. any idea?

Eye and joint pain: I would wonder if you have Lyme disease because it can explain eye and joint symptoms simultaneously.

Sacroiiliitis: An autoimmune arthritis sometimes known as Reiters Sydrome can cause iritis( inflammation of a part of the eye causing blurry Vision),arthritis (of the SI joint spine and large joints),and urethritis (symptoms like a urinary tract infection primarily burning on urination). Go see a rheumatologist.