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.
At sea level, a normal blood oxygen level (saturation) is usually 96 - 97%. Although there are no generally accepted classifications for severity of oxygen desaturation, reductions to not less than 90% usually are considered mild. Dips into the 80 - 89% range can be considered moderate, and those below 80% are severe.