DEAR DR. DONOHUE: My daughter was sent home from school with a note saying she had pinkeye and should stay home until the eye cleared up. I could see her eye was red, but she didn’t complain of much other than its watering. Is this overkill on the part of the school? – A.T.

ANSWER: Pinkeye is an infection of the conjunctiva, a cellophanelike tissue that covers the eye and attaches to the eyelids. Most of the time such infections are viral infections. They turn the eye red and make it water. Sometimes the eye feels gritty, and sometimes the lids stick together, particularly in the morning after a night’s sleep. There might be a swollen, tender lymph node in front of the ear on the side of the affected eye. Pinkeye patients – and they are usually children – generally don’t feel ill, and their sight is not impaired, but they might be sensitive to bright light.

Quite often, the second eye comes down with the infection, too. The child transfers virus from the eye where things started off to the other eye by rubbing the infected eye and then rubbing the other eye.

Viral conjunctivitis is quite catching. That’s why both eyes are almost always involved in time. The school was not overreacting. Your daughter’s entire class could have come down with it if she had been allowed to stay in school.

Ascertaining the cause of a pink (red) eye takes knowledge, skill and training. It can require special tests and special equipment. Not all red eyes come from viral infections. Allergies redden the eye. Uveitis, an inflammation of the middle eye layer, is a serious problem that reddens the eye and requires speedy treatment. An eye ulcer can also turn the eye red. That too requires quick treatment. In older adults, the uncommon variety of glaucoma, angle-closure glaucoma, turns the eye red. It’s a medical emergency.

The point to this is that a red eye should be examined by a doctor.

DEAR DR. DONOHUE: My sister has cancer. Her doctors have suggested surgery. She refuses. She believes that exposure of cancer to the air will make it spread throughout her body. Her husband and I would be indebted to you if you would set the record straight about this for her. Thank you. – P.M.

ANSWER: I don’t know where that idea got started, but it is entrenched in some people’s minds. Exposure to air does not spread cancer.

There is no basis in fact for this statement.

I hope you show this to your sister. Her delay in agreeing to treatment could tip the scales for cure away from her favor.

During a cancer operation, surgeons take great care in removing a tumor so that no cancer cells escape into the circulation and are transported to distant sites. Perhaps this lies at the bottom of her concern.

Dr. Donohue regrets that he is unable to answer individual letters, but he will incorporate them in his column whenever possible. Readers may write him or request an order form of available health newsletters at P.O. Box 536475, Orlando, FL 32853-6475.