An intravenous pyelogram may be used to diagnose disorders that affect the urinary tract, such as kidney stones, bladder stones, enlarged prostate, kidney cysts or urinary tract tumors. During an intravenous pyelogram, you'll have an X-ray dye (iodine contrast solution) injected into a vein in your arm. The dye flows into your kidneys, ureters and bladder, outlining each of these structures.
By Mayo Clinic Staff. Here are some of the most common causes of true under-eye circles. 1  Allergies. 2  Atopic dermatitis (eczema) 3  Contact dermatitis. 4  Fatigue.  Heredity â dark under-eye circles can run in families.
The pupil, the black spot in the middle of your eye, is actually a hole that allows light to enter the eye. Around this hole is the colored part of the eye, the iris, which regulates the size of the pupil and how much light is allowed into the eye. The iris has pigment in it to protect it against light. Everyone has pigment at the rear part of the iris, but not everyone has it at the front.