A flush valve is a mechanism used to flush a toilet or urinal. The valve and associated hardware are located within the toilet tank or in the body of the urinal. Most toilets have a lever or push button activator, which is used to operate the flush valve.
Photosensitivity (or sun sensitivity) is inflammation of the skin induced by the combination of sunlight and certain medications or substances.This causes redness (erythema) of the skin and may look similar to sunburn.hotosensitivity (or sun sensitivity) is inflammation of the skin induced by the combination of sunlight and certain medications or substances.
See also: Snow blindness (photokeratitis) Photophobia, or light sensitivity, is an intolerance of light. Sources such as sunlight, fluorescent light and incandescent light all can cause discomfort, along with a need to squint or close your eyes. Headaches also may accompany light sensitivity. Light-sensitive people sometimes are bothered only by bright light.