Eye colors depend on the amount of pigment (melanin) found in the iris and how it is distributed. Light gray-blue eyes contain much less pigment than extremely dark brown eyes. And there are many shades of eye color in between. SEE ALSO: What Determines Hazel Eye Color >.
Dystonia is a movement disorder in which a person's muscles contract uncontrollably. The contraction causes the affected body part to twist involuntarily, resulting in repetitive movements or abnormal postures. Dystonia can affect one muscle, a muscle group, or the entire body.ystonia can affect different body parts, and often the symptoms of dystonia progress through stages. Some early symptoms include: 1  A dragging leg. 2  Cramping of the foot. 3  Involuntary pulling of the neck. 4  Uncontrollable blinking.
Dystonia is generally characterized by involuntary muscle contractions that force the body into abnormal, sometimes painful, movements and positions (postures). Cervical dystonia is a form of dystonia that involves the neck area.