Sjogren's syndrome is an immunologic disorder characterized by deficient moisture production in glands that result in abnormal dryness of the mouth, eyes and/or other mucous membranes. It typically occurs in women over forty and is often associated with other conditions such as Raynauds phenomena, Rheumatoid Arthritis or lupus.
The fact that only one eye is involved suggests (but doesn't confirm) a localized infection. This may account for the effectiveness of the colloidial silver.