These are known as biogeochemical cycles. This is a very broad term given for any substance that cycles through biotic (biological) and abiotic compartments on Earth. These cycles are known for carbon, oxygen, nitrogen, phosphorus, sulfur, and water. The water or hydrological cycle is arguably the most well-known cycle. Water cycles between water vapor in the clouds, rainfall, rivers lakes and ocean as well as ground water and back into water vapour. During the terrestrial phase, water also passes through plants and animals.
Nyctalopia is the condition of night blindness characterized
by inability to see clearly at night or in dim light and the ability to see
clearly in the day. Deficiency of vitamin A leads to nyctalopia. Other possible
causes of Nyctalopia include myopia, cataract, retinitis pigmentosa and some glaucoma
medications.
