Symptoms depend on which muscles are affected. For example, when weakness affects muscles of the chest, people may have difficulty breathing. When weakness affects muscles that control the eyes, people may have double vision. Complete muscle weakness causes paralysis.
The choroid is the layer of blood vessels and connective tissue between the sclera (white of the eye) and retina. It is part of the uvea and supplies nutrients to the inner parts of the eye.
: a vascular membrane containing large branched pigment cells that lies between the retina and the sclera of the eyeâcalled also choroid coat.