Even though our eyes prefer even lighting, particularly between toss surfaces and its background out, I was able to adapt to a wide range of brightness levels. We can correspond to a minimum brightness ratio of two to one, as well as to a maximum brightness of 100 to one or even more, but only over a longer period of time. Our eyes cannot respond immediately to the extreme changes in lighting levels. Once our laws have adjusted to a certain level, any significant increase in brightness can lead to glare or eyestrain and impairment of visual performance. There are two types of glare, direct and indirect. Directly is caused by the brightness of light sources within our normal field of vision.

The brightness of the light source the grayed out the glare. possible solutions to problems of directly include the following. Locate the source of brightness out of the direct line of vision. If this is not possible, use properly shielded or baffled luminaries. In addition, raise the background brightness of the light sources and then reduce the brightness ratio