A heart attack occurs when the flow of blood to the heart is blocked, most often by a build-up of fat, cholesterol and other substances, which form a plaque in the arteries that feed the heart (coronary arteries). The interrupted blood flow can damage or destroy part of the heart muscle. A heart attack, also called a myocardial infarction, can be fatal, but treatment has improved dramatically over the years. It's crucial to call 911 or emergency medical help if you think you might be having a heart attack.
Irises are classified as being one of six colors: amber, blue, brown, gray, green, hazel, or red. Often confused with hazel eyes, amber eyes tend to be a solid golden or copper color without flecks of blue or green typical of hazel eyes. Blue eyes have a low level of pigment present in the iris.
Eye color or eye colour is a polygenic phenotypic character determined by two distinct factors: the pigmentation of the eye 's iris and the frequency-dependence of the scattering of light by the turbid medium in the stroma of the iris.ark brown eyes are dominant in humans and in many parts of the world, it is nearly the only iris color present. Dark pigment of brown eyes is common in East Asia, Southeast Asia, Central Asia, South Asia, West Asia, Oceania, Africa, Americas, etc. as well as parts of Eastern Europe and Southern Europe.