Lattice corneal dystrophy type II is a rare disorder cause by a genetic mutation. Clumps of protein build up in tissues throughout the body including blood vessels, nerves, corneas, and tear glands. The cornea is the clear covering of the colored part of the eye. The earliest signs of the condition usually happen in a person's twenties. The protein clumps build up in the cornea and can impair vision. It can cause damage to the corneas, which can be very painful, and cause sensitivity to light. This condition usually affects both eyes. The condition worsens with age, and around a person's forties it can affect the nerves, causing paralysis (inability to move) of facial muscles; decreased sensation in the face; difficulty speaking, chewing, and swallowing; and weakness in the limbs. Around the same time, it also affects the skin, causing thickened, saggy, itchy skin. Vision loss is usually not severe enough to require surgery and corneal transplants.