After we have already mentioned the lunate bone, one of the eight human carpal bones, which has been named after the Moon, due to its sickle shape, we would like to take another look at the human hand – this time at the fingernails. Lo and behold: here too, the name was inspired by the Moon. The white area of the nail, shaped like a half-moon is called »lunula« (lat. little moon) and incidentally, can be found on toenails as well. The lunula is differently pronounced with every human being, with some you may only see it on the thumb, with others you can see it on all fingers and toes.
»Moon blindness« (lat. morbus lunaticus) has nothing to do with the moonlight and luckily does not afflict humans. It is a disease of the eyes of horses, which recurs periodically. Due to an inflammation of the iris, which is caused by bacteria from food that has been contaminated by mice and rats, the cornea of the eye can cloud over. This leaves a bluish color, which gave the illness its name (even though the moonlight is not blue). If this inflammation continues to happen in an interval of months, it is possible that over the years it can lead to complete blindness of the animal. There is the option of an eye operation in the early stage of the illness, however, this is not straightforward.
There is actually a bone inside the human body, which is called »lunate bone«. Indeed, it may not belong to the most important of the 206 bones that a grown man carries around with him, but the name alone makes it remarkable. The lunate bone is one of the eight carpal bones, being the bones that connect the hand with the forearm. The lunate bone (lat.: os lunatum) was given his name because of its crescent shape.
As already mentioned in our article about sleepwalking, a connection was made in the past between the moonlight and people, if their conduct was odd, crazy or threatening. One assumed that the moonlight caused this behaviour and spoke of »lunatic«, which derives from the Latin »lunatus« and means more or less »influenced by the moon«. In English, this terminology »lunatic« has been used for many forms of mental illnesses over many centuries. Because many of these disorders could not be explained for a long time (and there are still plenty of questions today), one was in need of a point of reference, a word that would accompany on the path of darkness. The Moon was very convenient.
Sleepwalking is the term for a sleep disorder where the person concerned will move to an upright position in bed, or get up and walk around without waking up. It is also referred to as somnambulism, which derives from lat. »somnus« = sleep and »ambulare« = to wander. A further outdated term is »lunatism« and stems from the former belief that the light of the full moon coaxes the sleeper into leaving the bed. This misconception is scientifically disproved: sleepwalking takes place outside the lunar cycle.