Saline-Induced Hydrogel Lens Brunescence.

There have been many documented cases whereby hydrogel contact lenses have turned brown as a result of being stored in certain preserved saline solutions (see photo #1). The overwhelming majority of the color changes have been noted with the F.D.A. Group IV (high water, ionic) Lenses. Many possible causes have been speculated, such as: heating of extended-wear lenses in sorbate-containing solutions, storage or disinfection of dirty lenses in sorbate-containing solutions, and use of topical vasoconstrictors. It has further been speculated that interaction of tear film proteins with saline preservatives or the particular disinfection system may also be a contributing factor.