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.
There are multiple types of dystonia, and many diseases and conditions may cause dystonia. Dystonia is classified by. Clinical characteristics such as age of onset, body distribution, nature of the symptoms, and associated features such as additional movement disorders or neurological symptoms, and.