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.
Lagophthalmos is defined as the inability to close the eyelids completely. Blinking covers the eye with a thin layer of tear fluid, thereby promoting a moist environment necessary for the cells of the exterior part of the eye. The tears also flush out foreign bodies and wash them away.