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Title: Contact lens wear with the USAF protective integrated hood/mask chemical defense ensemble

Journal Article · · Aviation, Space and Environmental Medicine; (United States)
OSTI ID:7200678
; ; ;  [1]
  1. USAF, Armstrong Laboratory, Brooks AFB, TX (United States)

The Protective Integrated Hood/Mask (PIHM) chemical defense aircrew ensemble blows air from the mask's plenum across the visor at a rate of approximately 15 L/min in order to prevent fogging of the visor and to cool the aircrew member's face. This study was designed to determine the effect of the PIHM airflow on soft contact lens (SCL) dehydration, contact lens comfort, and corneal integrity. There were 26 subjects who participated in this study: 15 SCL wearers, six rigid gas-permeable (RGP) wearers, and five nonspectacle wearing controls. Contrast acuity with the three Regan charts, subjective comfort, and relative humidity (RH) and temperature readings under the PIHM mask were monitored every 0.5 h during 6-h laboratory rides. Slit-lamp examinations and SCL water content measurements with a hand-held Abbe refractometer were made before and after the rides. High RH under the mask may have accounted for the moderate SCL dehydration (8.3 percent), no decrease in contrast acuity for any group, and lack of corneal stress. Although all groups experienced some inferior, epithelial, punctate keratopathy, RGP wearers had the most significant effects. SCLs performed relatively well in the PIHM mask environment. Testing with other parameter designs is necessary before recommending RGPs with the PIHM system. 19 refs.

OSTI ID:
7200678
Journal Information:
Aviation, Space and Environmental Medicine; (United States), Vol. 63:7; ISSN 0095-6562
Country of Publication:
United States
Language:
English