Value, in terms of art, is the darkness or lightness of a color. Value is one of the seven elements of art and in many circles, it is considered to be the most important. Its importance in creating the illusion of light, form, and texture in a drawing or painting cannot be denied.
However, oxygen levels can vary greatly and have a large impact on how a person is able to function. As a consequence, medical professionals have developed standards for the amount of oxygen that should be present within a personâs body. For most people, an oxygen level of 95 percent to 100 percent is considered normal.
I am a 30-year-old woman. â January 12, 2012. Low blood oxygen, known as hypoxemia, means that the level of oxygen in the blood has fallen below normal levels, due to one or more of many different causes. Under most circumstances, breathing room air, normal readings range from 95 to 100 percent. Levels under 90 percent are considered low, so you probably are worrying unnecessarily. Oxygen levels are best measured via an arterial blood gas test that also measures carbon dioxide and pH or, less precisely, with an oximeter, a device that clips on the end of a finger and shines a light through it.