Correction of subtle refractive error in aviators.

Optimal visual acuity is a requirement for piloting aircraft in military and civilian settings. While acuity can be corrected with glasses, spectacle wear can limit or even prohibit use of certain devices such as night vision goggles, helmet mounted displays, and/or chemical protective masks. Although current Army policy is directed toward selection of pilots who do not require spectacle correction for acceptable vision, refractive error can become manifest over time, making optical correction necessary. In such cases, contact lenses have been used quite successfully. Another approach is to neglect small amounts of refractive error, provided that vision is at least 20/20 without correction. This report describes visual findings in an aviator who was fitted with a contact lens to correct moderate astigmatism in one eye, while the other eye, with lesser refractive error, was left uncorrected. Advanced methods of testing visual resolution, including high and low contrast visual acuity and small letter contrast sensitivity, were used to compare vision achieved with full spectacle correction to that attained with the habitual, contact lens correction. Although the patient was pleased with his habitual correction, vision was significantly better with full spectacle correction, particularly on the small letter contrast test. Implications of these findings are considered.