Keratoconus causes the middle of the cornea to thin, bulge outward, and form a rounded cone shape. This abnormal curvature of the cornea can cause double or blurred vision, nearsightedness, astigmatism, and increased sensitivity to light.
Bruises develop when small blood vessels under the skin tear or rupture, most often from a bump or fall. Blood leaks into tissues under the skin and causes the black-and-blue color. As bruises (contusions) heal, usually within 2 to 4 weeks, they often turn colors, including purplish black, reddish blue, or yellowish green. Sometimes the area of the bruise spreads down the body in the direction of gravity. A bruise on a leg usually will take longer to heal than a bruise on the face or arms.
The raised area of a bump or bruise results from blood leaking from injured blood vessels into the tissues, such as muscle, as well as from the body's response to the injury. A purplish, flat bruise that occurs when blood leaks out into the top layers of skin is called an ecchymosis.iny blood vessels near the surface of the skin can burst from a bump, a scrape, or injection-any kind of physical distress. Bruises change color like a mood ring as they mature (from black and blue to green to yellow) and last about one week on the face and two weeks on the body.