Psoriasis can affect the nails and produces a variety of changes in the appearance of finger and toe nails. Nail psoriasis occurs in 40â45% of people with psoriasis affecting the skin and has a lifetime incidence of 80â90% in those with psoriatic arthritis.
Color & Vision Matters. The human eye can see 7,000,000 colors. Some of these are eyesores. Certain colors and color relationships can be eye irritants, cause headaches, and wreak havoc with human vision. Other colors and color combinations are soothing. Consequently, the appropriate use of color can maximize productivity, minimize visual fatigue, and relax the whole body.
The human eye can function from very dark to very bright levels of light; its sensing capabilities reach across nine orders of magnitude. This means that the brightest and the darkest light signal that the eye can sense are a factor of roughly 1,000,000,000 apart. However, in any given moment of time, the eye can only sense a contrast ratio of one thousand. What enables the wider reach is that the eye adapts its definition of what is black.