This phase I study will determine the feasibility of the proposed methodology in assessing the potential use of ew contact lenses in an army aviation combat environment. It will accomplish this by: (a) evaluating fda manufacturers' data on chemical and physical properties of approved ew contact lenses; (b) pretesting, selecting, and fitting ew contact lenses to test subjects who are currently engaged in operational flying on a full time basis; (c) monitoring and recording the progress of the test subjects on a periodic basis utilizing both objective and subjective measurements; (d) correlating, analyzing, and evaluating all study data; (e) developing parameters for comparative evaluations of ew lenses based upon test study; and (f) submitting findings and recommendations to appropriate dod components.