Keratitis is a condition that affects the eyes of cats, and it may become a chronic disease that will ultimately affect the pet's vision. The condition will manifest through excessive tearing and ocular discharges. Keratitis can be treated once detected.he condition can dry the cornea and for this reason, it is also known as 'dry eye.' The causes of keratitis are not precisely determined, but certain factors may be suspected: 1  The feline herpes virus. 2  A foreign object that reaches the cornea. 3  An eye injury.
Quick Answer. The incubation period for head lice is between 6 and 9 days, or roughly one week. After hatching, young lice (nymphs) become adults in about 7 days. These adult lice can live on a human head for up to 30 days. Continue Reading.
Adult head lice can live for approximately  24 hours away from a host, according to the Centers for Disease Control. Nymphs, or young head lice, can live for only several hours away from a host. Lice eggs are less dependent on a host, and they can live for up to one week without a host.