Readaptation time after photo stress. Readaptation time as a function of oxygen concentration.

Optokinetic nystagmus (OKN) is used to study the eye's ReAdaptation Time (RAT) after a brief exposure to a light flash. The effects on RAT of breathing different concentrations of O2 are examined. Significant changes in RAT have been registered, showing that inhalation of 100% O2 as compared with room air, results in a shortened RAT (i.e. improvement), while inhalation of 9% O2 leads to an increased RAT (i.e. impairment). The physiology of RAT and the possible mechanisms behind the changes caused by different O2 concentrations are discussed. The findings of this group are compared with those of other studies.