Lagophthalmos is when the eyelids do not close completely, allowing exposure of the cornea. This can lead to discomfort, blurred vision and damage to the cornea. A common cause of lagophthalmos is cranial nerve VII palsy. This nerve controls facial expression, including raising the eyebrows, closing the eyes, and raising the angle of the mouth. Another common cause of lagophthalmos is thyroid eye disease. Depending on the cause and chronicity of the lagophthalmos, different procedures can be performed to help bridge the gap when patients close their eyes.