for example if you stare directly at a light source (at night) everything behind it should be practically impossible to see since you eyes have adjusted to the bright light and once you look away from the light there should be a few seconds if not minutes of recovery for your eyes to readjust to the dark.
right now the actual light source just seem to be another effect layer that has no effect on the player's sight, the glare should cover the majority of the screen to recreate the real life effect. it should really be added as it is a large scenario changer.