Bubble formation of aqueous humor and lens opacity during chamber flight

A transparent miniature decompression chamber was placed on the stage of a large-working zoom-stereo microscope so that the effect of decompression on the frog eye could be microscopically observed and photographed. It was found that chamber flight at a simulated altitude of 66,000 ft (20,117 m) or more caused bubble formation in aqueous humor and lens opacities in some of the experimental animals. On return to ground level, the bubbles either decreased in size or completely disappeared. The cataract could also regress after recompression to 1 atm. Such lens opacities may be termed altitude cataract, instead of asphyxial or anoxic cataract.