Pinkeye infections are often self-limiting. Kids may feel a little scratchiness and mild pain from the redness and inflammation of the white parts of the eye. This is why they tend to rub their eyes so much. Realize that we all touch the parts of our faces -- eyes, nose, and mouth -- constantly. So, it should not be a surprise when this infection spreads to the other eye or to other kids or family members. Usually vision is not affected except by the discharge of pus that may block sight temporarily.
Both bacteria and viruses cause pinkeye, but bacteria cause it twice as often. The diagnosis is made clinically. A culture of the pus from the eye is usually not necessary. Antibiotics shorten the duration of symptoms and decrease the spread to others. Eye ointments tend to stay about the eye longer than drops do and are usually easier to apply with less fuss. However, some kids do not like the blurry, sticky feel of their eyes for up to an hour or so after applying the medicine. Depending on the severity of the infection (usually mild), antibiotics by mouth are not normally needed.
The infection tends to resolve quickly with supportive measures. The best treatment is to have the kids keep their hands away from the eyes as best they can and to use frequent hand washing to limit spread. Clear away some of the pus that causes the eyelashes to stick together with a washcloth or cottonball and warm water. Once someone with pinkeye has been on the antibiotic eye medicine for 24 hours, they are no longer considered contagious and can return to school or daycare. I recommend using the medicine for 1 day after there is no more redness or gooey discharge from the eye.