These symptoms emerged just a few weeks ago. I called my chief resident to let her know. The protocol was for me to see the doctors at Wills Eye Institute, where I work, who would monitor my treatment. Yes, they said, you have pink eye. No, you cannot work.

These are the rules. Although I felt well enough to do my job, a resident in ophthalmology working with pink eye is a set-up for disaster. I could become the epicenter of an epidemic. I went home, banned from human contact as much as possible.

Pink eye, or conjunctivitis, is an inflammation of the clear tissue over the white part of the eye, caused by viruses or bacteria. The eye gets red, runny, itchy, and crusty, and it is extremely contagious.

Entire college campuses have been struck. The Centers for Disease Control and Prevention sent a team to Princeton in 2002 to investigate more than 300 cases. At Dartmouth the same year, 600 cases broke out.

Treatment is "chicken soup" for the eye: preservative-free artificial tears and cool compresses. If it's bacterial, antibiotic drops help. Both types get better on their own, but it's unpleasant. Some more vicious variations cause painful, mucous plaques called "pseudomembranes" and temporary blurry vision that may require steroid drops.

I have diagnosed several dozen cases of pink eye as a resident. So why did I succumb now? I wasn't wearing gloves when I took care of the patient who I believe gave it to me. But I did wash my hands for more than 30 seconds, and then sterilized all the equipment in the room. Somehow that virus still made its way into my eye.

Hand-washing has become something of a religious tenet at hospitals. Preventable infections kill an estimated 100,000 people a year. Last month, a doctor, Peter J. Pronovost, won a MacArthur "genius" grant for developing a simple checklist that cut down infections by two-thirds in a group of very sick patients. The first box in that checklist is to wash hands thoroughly.

My hospital does its part by making sure that eye infections don't travel from one patient to another. Signs adorn the ER where I work: "Ask Me If I've Washed My Hands."

But pink eye is a formidable foe. The first report of the eye disease came in 1889 in Austria. A decade later, an outbreak struck 3,500 people in a slum in Madras, India.

The first report in the United States was in 1938 at a Veterans Administration hospital in California. In 1941 a famous outbreak hit Hawaii: 10,000 people in a naval shipyard came down with the bug. It became known as "shipyard eye."

Since then, it's been known to blanket entire worksites, and summer camps. Investigators have traced outbreaks in eye clinics and hospitals to use of contaminated examination equipment and ophthalmic drops. One study has shown that the viruses can survive up to 49 days.

It makes you wonder why we let pink eye patients into our offices. The answer is that not all red eyes are pink eyes. A red eye could be the result of things you would not want to miss: undiagnosed glaucoma or even eye cancer.

A new cutting-edge device being tested at Wills may make pink eye diagnoses easier. A swab to the eyelids collects tear fluid. It's then placed in a device for a pregnancy test-like read-out: one line for negative, two lines for positive.

I would never recommend picking up a case of pink eye as a learning tool. But I now know exactly what patients mean when they say, "I feel like something's in my eye." And I am closer to understanding the disabling experience of blurry vision.

Now that I have been estranged from work for two weeks - and worried about transmitting it to family members while I'm home - there isn't anything that I want more than my health. So I'm looking forward to getting back to work and taking care of patients - even if they have pink eye.