What is Pink Eye?

What is Pink Eye?

Conjunctivitis, commonly called pink eye, is inflammation of the membrane (conjunctiva) that lines the eyelids and covers the white part of the eyeball. The irritation of pink eye can be a symptom of an allergic reaction.

Pink eye does not usually affect a person’s long-term vision. However, the symptoms of pink eye cause annoying discomfort and irritation, making the eyeball feel gritty and dry. The small blood vessels in the membrane lining the eyelids and whites of the eyeball (conjunctiva) become irritated and inflamed, making them appear red or pink—hence, the name pink eye.

Pink eye can sometimes be contagious if caused by an infection. Treating pink eye with medication may offer significant relief for the uncomfortable symptoms. Therefore, make an appointment with a primary care specialist if you are experiencing the irritating symptoms associated with pink eye; if these symptoms last longer than 24 hours, they could be a sign of an eye infection.

Types of Pink Eye


There are three types of pink eye, also known as conjunctivitis: bacterial, viral, and allergen- related. Pink eye can also be brought on by getting something in your eye, like sand or a piece of a foreign object. Chemicals and pollutants can bring about allergic reactions that cause pink eye.

  • Bacterial conjunctivitis is a rare inflammatory infection of the eye caused by direct contact with infected secretions. The most common causes of bacterial pink eye are:
    • Staphylococcus aureus (staph infection)
    • Haemophilus influenzae (bacterial infection found mostly in babies and children)
    • Streptococcus pneumoniae (pneumococcal disease)
    • Moraxella catarrhalis (common cause of inner ear infections and sinus infections)
    • Chlamydia trachomatis (sexually transmitted disease that can be passed from the mother to the baby during childbirth)
    • Neisseria gonorrhoeae (a sexually transmitted disease affecting the mucous membranes of the reproductive tract that can be passed along to an infant during childbirth)
  • Viral conjunctivitis, or viral pink eye, is the most common and most contagious form of conjunctivitis caused by a virus. It is usually transmitted via hand-to-eye contact or by touching an object that someone infected with pink eye has touched and then touching your eye. Viral pink eye, or infectious conjunctivitis, is easily transmitted through infectious tears or infected eye discharge. Hands that have been contaminated with contagious respiratory droplets can also cause viral conjunctivitis.
  • Allergic conjunctivitis. When the eyelids' lining and the eyes' whites are irritated by an allergen, pink eye is the inflammatory response. This is usually a seasonal reaction associated with upper respiratory tract allergic reactions to pollen, pet dander, mold, dust, or other airborne allergens.

Signs & Symptoms of Pink Eye


A person’s eyes become red and inflamed-looking as pink eye symptoms are very irritating and annoying.

The general signs and symptoms of conjunctivitis can include:

  • The white part of someone’s eyeball may be red or pink in color (because of irritated blood vessels)
  • The conjunctiva (the thin membrane that protects the white part of the eyes and the inside of the eyelids) may swell, causing irritation
  • Persistent tearing
  • You may feel like you have something in your eye
  • Burning, itching, and constant irritation of the eye

If constant eye irritation continues for more than 24 hours or you experience symptoms such as blurred vision or severe pain, contact your primary care specialist or one of the experienced physicians in the Division of General Internal Medicine at NewYork-Presbyterian.

Their knowledge and experience in all types of general health problems can assist in ascertaining whether they can treat your eye condition or they may recommend a NewYork-Presbyterian ophthalmologist (eye doctor) further examine your eye condition.

What Causes Pink Eye?


Many things can cause pink eye; getting something in your eye could result in pink eye. However, the most common causes of pink eye are:

  • Viral infection. Most pink eye cases are caused by the adenovirus—the common cold virus. However, other viral infections such as herpes simplex, varicella-zoster, COVID-19, and other viruses can cause pink eye.
  • Bacterial infection. Wearing contact lenses that are not cleaned correctly or wearing another person’s contact lenses can result in bacterial conjunctivitis.
  • Allergen-related. Those with seasonal allergies to pollen or allergies to pet dander can experience pink eye.
  • Toxic exposure. Getting splashed with toxic chemicals in your eyes or toxic chemicals in the air can cause pink eye.
  • Getting something in your eye. A scratch from a foreign object getting in your eye could become infected, causing pink eye.
  • Dry eyes
  • Blocked tear duct. This is more common in infants.

Risk Factors for Pink Eye

Risk Factors

Some leading risk factors for pink eye include:

Infective pink eye

  • Wear contact lenses that have not been properly cleaned
  • Touching infected surfaces from either viral or bacterial conjunctivitis
  • Crowded living or working places such as schools or military barracks
  • Poor hygiene

Infants with conjunctivitis

  • Contracting infection from mother during childbirth
  • Premature rupture of membranes (PROM)
  • Exposure to silver nitrate
  • Unsanitary delivery conditions
  • Premature birth

Allergic conjunctivitis

  • Being exposed to pollen from trees and plants
  • Exposure to pet dander
  • Exposure to toxic chemicals

History of eye disease

  • Having a history of eye disease
  • Recent eye surgery
  • Immune compromised
  • Thyroid eye condition
  • Autoimmune disorders
  • Diabetes

How to Prevent Pink Eye


Preventing pink eye in certain situations may be difficult, but following these solid suggestions could help you avoid germs that lead to eye contamination and conjunctivitis:

  • Wash your hands often
  • Avoid touching your eyes
  • Change your bed linens often
  • Do not share your cosmetics or eye care products with anyone else

Environmental situations, such as avoiding exposure to pollen or toxic chemicals, could be difficult to control. However, if you know being in certain conditions causes eye irritation, avoid these settings if you can and wear protective goggles as the guidelines recommend.

Get Care

Trust NewYork-Presbyterian for Pink Eye Care

The doctors and healthcare professionals at NewYork-Presbyterian are leaders in all fields of medicine, providing the most innovative and advanced care available. In addition, NewYork-Presbyterian has healthcare professionals specializing in ophthalmology located in our eye care centers throughout the New York metropolitan area.

Call one of our centers for same-day appointments for critical needs.

Know your treatment options and visit one of our eye care centers if you suspect you may have developed pink eye or another eye condition.