 Uveitis is a group of troublesome diseases that collectively represent a cause of blindness comparable to diabetes. Most forms of uveitis are either infectious or immune-mediated. The investigators propose to create a data base on peripheral blood gene expression for patients with 3 of the most important diseases associated with uveitis: ankylosing spondylitis, sarcoidosis, and Behcets disease. The investigators will quantitatively measure the expression of consistent alteration in peripheral blood from patients with more than 40,000 gene sequences using microarray gene chip technology. This approach is known to detect systemic immune-mediated disease. The investigators will use this data base to: 