On the relation between glare and straylight.

An overview is given of the basic phenomena that may lead to glare complaints in patients. Prominent among them is increased intraocular straylight; this can be measured. Other causes may include: increased sensitivity to normal straylight, the length of (increased) light and dark adaptation times, (small angle) neuronal lateral interaction. Distinction must be made between disability glare and discomfort glare. Tests have been proposed to determine glare-induced loss of various visual functions. Often the test results are thought to be directly related to straylight but this may be untrue.