It has also been found the fluctuating light levels due to the inclusion of lighting systems in caves to aid in visibility for human access can have detrimental effects on the organisms within a cave. It has been found that the exposure to light can cause glow worms to dim their display, which holds potential detrimental effects to tourism built on glow worm show caves. Another detrimental effect of artificial lights is that they have been seen to cause algae and cyanobacteria to grow in places that they would not usually grow, and the organic acid produced when they grow can potentially damage speleothems and cave paintings.