Of course there is the well known connection between celiac and Sjogren's, which causes severe dry eye. There is a simple test (the Schirmer test) for the dry eye where they put little strips of blotter paper in your eye and see how long it takes them to get damp, lots of fun (NOT!)
http://0-www.ncbi.nlm.nih.gov.catalog.llu....0?dopt=Abstract