Published on: April 7, 2023 || Last Modified: August 11, 2026
By Dr. Kenneth King | Alliance Vision Institute
Dr. King is an ophthalmologist at Alliance Vision Institute in Fort Worth, TX.
Pink eye is one of the most common reasons people call an eye doctor, and one of the most misunderstood. It is not one condition. It is a catch-all term for anything that turns the white of the eye red or pink. Here is what you actually need to know.
Pink eye, or conjunctivitis, refers to inflammation of the conjunctiva, the clear membrane covering the white part of the eye. When it becomes irritated or infected, blood vessels dilate and the eye turns pink or red.
The problem with the term “pink eye” is that it describes a symptom, not a cause. A viral infection, a bacterial infection, an allergic reaction, and a simple irritant can all produce a pink or red eye. Each one requires a different response. Treating the wrong cause with the wrong medication does not help and can make things worse.
Viral conjunctivitis is the most common type seen in an eye doctor’s office. It is caused by viruses, including common cold viruses, and in more serious cases, shingles or other herpes-family viruses. The eye is usually pink or lightly red, watery, and uncomfortable. Most viral pink eye runs its course on its own. The more serious viral forms do require treatment, which is why getting the correct diagnosis matters.
Bacterial conjunctivitis produces more noticeable discharge. The eye becomes goopy, mucusy, and may crust shut overnight. Bacterial infections typically do respond to antibiotic eye drops, but only an eye doctor can confirm that bacteria is actually the cause.
Allergic conjunctivitis is driven by the immune system reacting to pollen, pet dander, dust, or other allergens. It tends to affect both eyes, often comes with itching, and is managed very differently from infectious pink eye.
Contact lens-associated red eye (CLARE) is its own category. Contact lens wearers who develop a red eye need to be seen promptly. The combination of a lens and an irritated or infected eye creates additional risk and requires specific evaluation.
Most mild pink eye can wait for a scheduled appointment. Some symptoms should not wait:
If you wear contact lenses and develop a red eye, do not put it off. The risk profile is higher and early treatment is much easier than managing a worsened infection.
The most common way any eye infection spreads is hand-to-eye contact. You touch a contaminated surface, then touch your eye. That is how the virus or bacteria is introduced, and it is called inoculation.
Viral pink eye, particularly a strain called epidemic keratoconjunctivitis (EKC), is highly contagious. The virus is shed in tears and eye discharge and spreads easily through shared surfaces and direct contact.
If you or someone in your household has pink eye:
You can give yourself pink eye in the second eye by touching the infected eye and then touching the other. It does not migrate on its own. You have to put it there.
This is one of the most common misconceptions in eye care, and it causes real problems.
Antibiotics treat bacteria. They have no effect on viruses. Viral conjunctivitis is actually more common than bacterial conjunctivitis. Reaching for an old antibiotic eye drop or a tube of Neosporin when you have a viral infection does nothing to treat the virus and may irritate already inflamed tissue further.
Do not use leftover eye drops from a previous infection to treat a new one. Different medications treat different conditions. What worked for something else may make a new problem worse. See your eye doctor so the cause can be identified and the right treatment prescribed.
Pink eye does not discriminate by age. Adults get it regularly, often catching it from their own children. A child gets a cold, the parent wipes the child’s face, touches their own eye, and ends up with viral conjunctivitis. That inoculation pathway works at any age.
No. This one has circulated for years and has no basis in reality. Pink eye requires direct contact with the virus, bacteria, or allergen through the eye. Airborne transmission of that kind is not how conjunctivitis works.
Primary care doctors can handle straightforward bacterial pink eye reasonably well. Where they are limited is in differentiating between causes and examining the eye under magnification. An eye doctor uses a slit lamp microscope to look at the conjunctiva, cornea, and surrounding structures in detail. That level of examination is what separates a confident diagnosis from a guess.
Allergic reactions, viral infections, contact lens complications, and corneal involvement all require a more specific look than a primary care visit typically provides.
Keep the eye lubricated with preservative-free artificial tears. This helps rinse the surface and reduce irritation. Do not use any prescription or over-the-counter drops left over from a previous condition without checking with your eye doctor first.
Pink eye is not a single condition. Viral, bacterial, allergic, and contact lens-related causes all produce a red or pink eye and each requires a different treatment. Antibiotics are not a universal fix. See your eye doctor for a proper diagnosis, especially if there is pain, vision changes, significant light sensitivity, or heavy discharge. When caught early, pink eye is usually straightforward to manage.
If your eye is red, pink, or uncomfortable and you are not sure what is causing it, our team can get you evaluated and on the right treatment quickly.
Schedule an appointment at Alliance Vision Institute
Explore more eye health topics in the Days of Our Eyes series with Dr. Kenneth King and Dr. Christopher Cha.