Recovery time of the human eye after exposure to laser light

Bright light can temporarily reduce the visual capacity of the human eye. Especially in traffic or in dealing with lasers disability glare can considerably reduce the visual faculty and lead to accidents. Even after the glare light has disappeared out of the field of vision, the visual capacity can still remain reduced for seconds or even minutes. It is therefore indispensable to investigate the recovery time of the human eye after glaring and to determine limiting exposures in order to avoid accidents or possible eye damage. We report on measurements of the recovery time in the range from 475 nm to 650 nm performed with thermal sources. Experiments are reported on the influence of varying intensities of test and glare light applied in the line of sight or extrafoveally. These studies allow us to give an empirical formula for the recovery time. In the present contribution we also report on measurements as a function of the duration of glaring. The range from 20 microsecond(s) to 1 s has been covered with an Argon laser at 488 nm as glare source. The resulting recovery time in different regions of this very large time scale will be discussed.