Brown eyes are, for the most part, not a sign of any physical problem, but rather a sign of pigmentation in the iris as determined by heredity and other factors, but it should be noted that pathological conditions such as biliary obstruction can also lead to brown eyes. For most yellow Asians, the iris itself is brown due to heredity and other factors. When viewed in the light or at close range, the color of the iris in most cases is what the average person would describe as the color of the eye, and brown is mostly normal. However, it cannot be ruled out that due to pathological conditions such as biliary obstruction, the bilirubin in the body may be abnormally high, thus causing the conjunctiva to change from white to yellow or brown, a situation that requires attention. The sudden appearance of brownish-yellow color changes in the conjunctiva, etc., should promptly consult a doctor to improve the bilirubin and other biochemical tests to determine the cause.