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.
Head lice survive less than one or two days if they fall off the scalp and cannot feed. Head lice eggs (nits) cannot hatch and usually die within a week if they do not remain under ideal conditions of heat and humidity similar to those found close to the human scalp. The head lice may have become resistant to the treatment. 2  If the treatment used does not kill the head lice, your health care provider and pharmacist can help you be sure the treatment was used correctly and may recommend a completely different product if they think the head lice are resistant to the first treatment.