Considerations in Contact Lens Use Under Adverse Conditions Proceedings of a Symposium (1991) / Chapter Skim
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Corneal Effects of Extreme Environments: Considerations for Pilots Wearing Contact Lenses
Corneal Effects of Extreme Environments: Considerations for Pilots Wearing Contact Lenses
Pages 97-105
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From page 97... ...
study of free-falljumping parachutists fitted with soft lenses revealed that, when lenses were blown off the eye, corneal epithelial punctate staining and temporarily reduced visual acuity occurred. ULTRAVIOLET RADIATION AT HIGH ALTITUDES increased ultraviolet radiation is a risk at higher altitudes.
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From page 98... ...
tested subjects wearing soft contact lenses for 1 hour in an environment where the temperature was kept at 50 C, the relative humidity was 20 percent, and the wind speed was 1.5 meters per seconds. They found no significant subjective or objective changes in vision or comfort.
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From page 99... ...
EFFECTS OF ALTITUDE ON THE CORNEA Two studies that investigated the effects of reduced atmospheric pressure on subjects wearing contact lenses showed significant adverse ocular effects. All other studies reported minimal adverse ocular effects.
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From page 100... ...
Visual acuities were 20/20 or better throughout the flight simulation. Although visual acuity fluctuations occurred 19 times in 6 of 8 soft lens wearers and 12 times in 4 of 8 subjects wearing spectacles, these were not considered to be significant and could not be attributed to the con atmospheric pressure.
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From page 101... ...
Therefore, the authors suggested that, although the exposure was limited and prolonged repeated exposures combined with additional aircraft environmental factors may hypothetically severely affect the physiological response of the cornea to adversely affect vision, soft contact lenses can be worn while flying. Brennan and Girvin (1985)
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From page 102... ...
IMPRESSIONS OF PREVIOUS RESEARCH AND RECOMMENDATIONS From the available studies it would seem likely that aircraft pilots can wear soft and hard lenses in FAR and TTB aircraft cabin environments with minimal risk of ocular or visual complications. However, the errors in the test parameters such as 40 percent more or humidity when the typical relative humidity in a cabin environment is much lower, lack of controls in some studies, and conflicting results make it advisable that further controlled testing be completed.
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From page 103... ...
Marano 1978 Low atmospheric pressure effects on wearing soft contact lenses. Aviation, Space, and Environmental Medicine 49~1~:73-75.
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From page 104... ...
Clemens 1987 Corneal ulcers associated with cosmetic extended wear contact lenses. Ophthalmology 94:109-1 14.
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From page 105... ...
Pettit, and J.D. Hofbauer 1984 Corneal ulcers associated with extended wear soft contact lenses.
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