Sudden stinging, tearing and redness of the eyes are likely to be caused by acute dacryocystitis. Ocular infections, including Staphylococcus aureus and Streptococcus haemolyticus infections, are common due to a decrease in eye resistance caused by factors such as excessive eye use. In children, the symptoms may also be caused by Haemophilus influenzae infection. Stinging and tearing eyes caused by keratitis are usually accompanied by photophobia and vision loss.