Contact Lens Wear for Visual Disorders in USAF Aviators

Contact lenses are an alternative method to spectacles for correcting refractive errors, but the U.S. Air Force prohibits the wearing of contact lenses by all aircrew members unless medically or optically indicated (AFR 167-3). The USAF School of Aerospace Medicine has a clinical contact lens study consisting of 55 individuals wearing contact lenses for eye defects such as keratoconus, aphakia, anisometropia, and other special indications. Of these 55 subjects, 33 had medical conditions affecting their vision and were unconditionally grounded. Thirty-one of these individuals (18 of 19 pilots, 8 of 9 navigators, 5 of 5 other categories) were visually rehabilitated and returned to full flight status by the use of contact lenses. Hard lenses were used in 70% of the cases, and soft lenses were used in 30%. The large number of USAF aviators required to wear spectacles and new head-borne equipment has created compatibility problems with the standard USAF aviators' spectacle. For this spectacle compatibility problem, contact lenses appear as a viable alternative. However, concerns remain about the potential aviation hazards, such as +G2 effects, bubble formation and corneal hypoxia.