We measured the potential toxicity of four contact lens solutions using an in vitro approach in which the optical quality of the cultured bovine lens was measured as a function of exposure to each substance tested. This approach uses an automated scanning laser to measure the focal variability of lenses contained in special culture cells and maintained under long-term culture conditions. The products tested included three rigid gas permeable contact lens conditioning solutions (Boston Conditioning Solution, Boston Advance Conditioning Solution, and a new formulation of Boston Advance Conditioning Solution [Polymer Technology]) and one soft contact lens disinfecting system (OptimEyes; Core Technologies). The results indicate a wide range of toxicologic potential that corresponds, on a relative basis, with published in vivo evaluation of the same substances. Moreover, the results demonstrate that this in vitro system can be used to evaluate the potential for recovery from damage caused by the four solutions tested.