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.
A head louse lives on average 30-days after it hatches from the egg. Eggs take around 7-days to mature and then hatch. Newly hatched head lice are fully mature in just 7-10 days. Therefore, most are active in your hair for about 21-days.