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.
Highlights. 1  Photosensitivity is an extreme sensitivity to ultraviolet rays from the sun. 2  This condition can lead to rashes and burns. 3  Photosensitivity can be caused by side effects of certain medications.