We examined the effect of hypoxia on the human light rise measured by electooculography. Experiments were performed on three subjects. EOGs were recorded by conventional methods. The stimulus was a diffuse field dimmed gradually over 30 min from 350 to 0.35 td, followed by a step to 6250 td. Ten minutes before the light step, the observer began inspiration of 10% O2 to induce hypoxia, or continued breathing air through a mask or breathing tube. Arterial O2 saturation was monitored continuously with an ear oximeter and during hypoxia decreased from 96-99% to 70-88%. During hypoxia the standing potential increased during the dim light conditions of the ramp. The light step induced only a small further increase in potential. In a second protocol, we examined prolonged hypoxia during continued adaptation to 0.35 td. During prolonged hypoxia, the standing potential returned to nearly its prehypoxic level. Two of three observers showed a subnormal light rise, suggesting that hypoxia has a specific effect on the light rise in addition to the initial elevation of the standing potential in the dark.
|Original language||English (US)|
|Number of pages||6|
|Journal||Clinical Vision Sciences|
|State||Published - 1987|
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