Background The goal of this study is to examine the human visual and cognitive performance
under the effect of bright light pulses. Exposure to visual stimulation of such pulsation may
interfere with cognitive function and at certain situations this may be noticeable and may
interfere with our judgment and abilities. In some of them visual or cognitive impairment
from exposure to bright light flashes may result in catastrophic outcome due to the high-risk
situation e.g. road accidents. Ocular exposure to a bright light can result in profound
momentary transitional loss of vision. The light sources employed for visual stimulation in
this study will be restricted to the range consistent with "reversible effects" (e.g. glare
and flash insensitivity or "flash blindness").
The impact of an exposure to bright light depends not only on the exposure level and
frequency, but also on the exposed individual's activity, psychological state, adaptation
level and visual task. Glare is primarily caused by the scattering of light within the eye
due to the imperfect transparency of the optical components of the eye and to a lesser extent
by diffuse light passing through the scleral wall or the iris. The scattered light overlays
the retinal image, thus reducing visual contrast. Excessive glare may impair visual function
and lead to temporary disability.
The above mentioned effects of exposure to light and pulsating light stimulus on the visual
system and cognition were studied in detail by a number of groups. These studies indicate
that the visual and cognition effects of pulsating light are a function of the following
parameters: pulse duration, light intensity and pulse frequency.