What Causes Pink Eye (Conjunctivitis)?

Baptist Eye Surgeons • December 8, 2021

Pink eye is a frustrating eye infection that can make your eyes feel uncomfortable and you feel embarrassed. It leaves you with eyes that are red as well as irritated, inflamed, and uncomfortable. But what causes pink eye and, more importantly, what can you do about it?

Pink eye can occur for a number of reasons, including viral infections, bacterial infections, allergies, and foreign bodies entering your eye. It’s more common in cold and flu season, making it extra important to wash your hands and sanitize surfaces. Symptoms can include redness in the eye, swollen eyelids, and watery discharge. Viral cases will heal on their own, but bacterial infections require medical treatment.

What causes pink eye?

Also known as conjunctivitis , pink eye is when the clear membrane that lines your eye and eyelid ( conjunctiva ) becomes infected or inflamed. This causes the blood vessels in the membrane to turn red or pink and become much more visible than usual, hence the nickname “pink eye.”

Pink eye can have multiple causes. In fact, it’s often a catch-all for whenever the eye becomes irritated and red. However, the medical term “conjunctivitis” actually refers to a:

  • Viral infection
  • Bacterial infection
  • Allergic reaction
  • Irritation

Pink eye is also common in infants due to tear ducts that haven’t opened completely. It can also be caused by foreign objects or chemicals that have found their way into your eye.

Viral Infections

Viral and bacterial infections are the most common causes of pink eye. Viral infections are usually due to the adenovirus , but they can also be caused by the herpes simplex virus , varicella-zoster virus , and the coronavirus that causes COVID-19. 

Bacterial Infections

Bacterial infections can occur in a number of ways, including contact lenses and expired eye makeup . This is why it’s so important to clean your contacts regularly and never sleep in them. You should also replace makeup every 3 – 4 months, never share makeup, and keep your brushes and applicators clean.

Allergic Reactions

Allergic conjunctivitis occurs when you’ve been exposed to substances that you’re allergic to, such as pet dander or pollen. It affects both eyes and is your body’s way of fighting off perceived threats. In the fight to protect itself, your body releases histamines that cause other allergy symptoms such as sneezing and nasal discharge.

Irritation-Related Conjunctivitis

Sometimes you may get a foreign body such as sand or, worse yet, a chemical splashed in your eye. These can be minor irritants that pass with time or by properly flushing your eyes. On the other hand, they can also lead to long-term problems due to corneal abrasions or more caustic chemicals. Contact your eye doctor immediately if you experience these problems.

Click here to read our blog about corneal abrasions and how they can affect your vision.

Is pink eye more common in cold and flu season?

A young girl is wiping her eyes with a napkin.

You can get pink eye any time of year, but you’re much more likely to get it during the winter. This is due to direct contact, which is the same reason the cold and flu are so common during this time. People spend more time inside this time of year, and hugging during the holidays also increases your risk. However, you’re more likely to pick it up from the surfaces of objects, so make sure to clean and sanitize after you have guests

You’re more likely to spread it to others if you have viral or bacterial pink eye during winter, so it’s important to take precautions. You can do this by:

  • Washing your hands regularly
  • Avoiding touching people who have it
  • Avoiding or sanitizing surfaces that may be contaminated

You can also avoid conjunctivitis by getting some sun or talking to your doctor about taking a vitamin D supplement. The vitamin D we get from the sun’s rays is essential for a healthy immune system, but it’s harder to get when it’s cold and cloudy. You can protect yourself by making getting sunlight a priority this time of year, even if it’s just for a few minutes, and supplementing with a vitamin.

Click here to read our blog where we go deeper into the connection between conjunctivitis and winter.

Pink Eye Symptoms

Symptoms of pink eye are similar no matter what time of year you catch it. Common symptoms include:

  • Redness of the eye
  • Swollen eyelids
  • Discharge from the eye
  • An itchy, burning, or stinging sensation

No matter the cause or your symptoms, our team of ophthalmologists is here to help you. They can determine what type of pink eye you have in order to treat your condition.

Treating Pink Eye

Be sure to have your eye or eyes checked by your eye doctor if you have pink eye symptoms. You can’t know what type you have on your own, but they will. Viral cases go away on their own, but bacterial conjunctivitis will require medical treatment in order for it to get better. This may include using antihistamines and anti-inflammatories to get rid of the bacteria.

Your eye doctor will be able to recommend over-the-counter (OTC) eye drops or other medicines that can help. They can also give you advice on the best types of OTCs for your particular situation.

Are you concerned that you may have pink eye? Contact us today to schedule your appointment!

Viral infections, bacterial infections, allergies, and foreign substances can all cause pink eye. You’re actually at an increased risk for infection in colder months due to higher chances of direct contact with people or surfaces carrying viruses or bacteria. Common symptoms include eyes that are red, watery, and itchy. While viral cases will pass on their own, bacterial conjunctivitis will require medical treatment.

Baptist Eye Surgeons is an ophthalmological practice in Knoxville, TN, and Morristown, TN. Give us a call at 865-579-3920 for more information or to schedule an appointment .

Dry Eye & Allergies: How to Tell the Two Apart

October 29, 2026
Dry, itchy or watery eyes can make simple day to day activities quite uncomfortable, particularly if the symptoms are affecting your ability to read, work or enjoy time outside. The two most common causes of eye discomfort are dry eye disease and eye allergies. They can present in a very similar way so it's important to be able to differentiate between the two in order to know when you need to see an eye care professional. An eye examination at Baptist Eye Surgeons will help to establish the cause of your symptoms and will allow us to recommend the most appropriate treatment. What is the difference between dry eye and eye allergies? Dry eye disease is essentially the condition where your eyes either aren't producing enough tears or the tears produced are evaporating too quickly to adequately lubricate the surface of the eye. The result is typically irritation, redness, a gritty feeling and sometimes quite the opposite of what you'd expect in the form of excessive tearing. Eye allergies (allergic conjunctivitis) are basically your immune system reacting to an allergen (pollen, dust mites, mold, pet dander etc). The result of that reaction is the release of histamine and other mediators which can lead to itching, redness and swelling. As both conditions may result in red, watery and uncomfortable eyes, it's important to be able to recognize the specific symptoms in order to get to the root of the problem and find relief. Dry Eye vs. Allergies: Common Symptoms to Watch For Although there is some overlap between the two conditions there are certain symptoms which may help you to tell them apart. 1. Itchy Eyes vs. Burning and Grittiness One of the most obvious differences is the kind of discomfort you're suffering. Eye allergies are very much associated with intense itching (to the point where you're constantly itching the eyes) and with swelling of the eyelids. Dry eye disease is more likely to cause a burning, stinging sensation (as if something is in your eye) or a gritty feeling. Your eyes will often feel tired and/or irritated, particularly after reading, working at a computer or being in an air conditioned environment. 2. Watery Eyes and Excessive Tearing Both dry eye and allergies can lead to watery eyes, just that the mechanism is different in each case. With dry eye disease, irritation can trigger a reflex which results in an overproduction of watery tears. These tears may well be in fact more of a problem than a solution as they won't provide the sustained lubrication that your eyes require. With allergies you often get watery eyes along with itching, redness and swelling of the eyelids. These can become quite apparent after exposure to pollen, dust and so on. 3. Seasonal Symptoms and Environmental Triggers The timing of your symptoms can be of some use in terms of giving you a clue. Eye allergies are a common problem and tend to be worse at certain times of year (particularly when pollen counts are high). They can also occur year-round if you're exposed to indoor allergens such as dust mites and pet dander. Dry eye symptoms can occur all year round and can be made worse in dry, windy or air conditioned environments. Lengthy screen time, ageing, certain medications and some medical conditions may all contribute to dry eye disease. 4. How Symptoms Affect Both Eyes Allergic conjunctivitis will typically affect both eyes and is very often associated with quite marked itching. Dry eye can also affect both eyes, though the symptoms may be quite different in the two eyes. Neither pattern alone is definitive for determining the cause of eye irritation. How Are Dry Eye and Eye Allergies Diagnosed? An eye exam enables your eye care professional to assess your symptoms, take your medical history and look for any signs of irritation or inflammation. Depending on your symptoms, the testing may look at tear production, tear quality, tear evaporation and the surface of the eye. Your eye care professional may also look at environmental triggers and other conditions which may be playing a part in your symptoms. Accurate diagnosis is important as dry eye and allergies can require different treatments and in some cases both can be present at the same time. How can you find relief from eye irritation? Treatment is dependent on the etiology of your symptoms. Artificial tears may be of some help in the relief of dry eye discomfort, allergy medication or antihistamine eye drops may be of benefit in the management of allergic symptoms. Your eye care professional will be in a position to advise you on the most appropriate options for you. Don't rub your eyes and consider minimizing exposure to any known irritants/allergens. If the symptoms continue, get worse or keep coming back then you should have an eye exam rather than just carrying on treating them without knowing the actual cause. Get prompt medical attention for severe eye pain, sudden change in vision, intense light sensitivity or severe redness. Protecting Your Eye Health Knowing the difference between dry eye and allergies can go a long way to helping you understand your symptoms and get to the root of the problem so that you can take appropriate steps to alleviate them. The issue is that the two conditions can present with such similar symptoms that a proper assessment by a professional is often the only way to work out which one you actually have. If you are experiencing persistent itching, burning, redness, or watery eyes, schedule an appointment with Baptist Eye Surgeons. An eye care professional can help identify the source of your symptoms and develop a treatment plan to support your comfort and long-term eye health. 

What to Expect During Your First Eye Exam: A Step-by-Step Guide

September 22, 2026
A thorough eye exam is an important part of keeping your vision healthy and protecting your eyes. If you are arranging for your first eye examination as an adult, if you are taking a child in for an evaluation, or if you have noticed any changes in your vision, knowing what to expect can help make the experience more comfortable. The eye exams carried out at Baptist Eye Surgeons not only check your vision but also look at your general eye health and spot any possible problems that might call for further investigation. What is the Importance of Eye Examinations? An eye examination does not merely enable one to find out if glasses or contact lenses are required. It lets an eye care professional assess how well your eyes are working and spot the signs of common eye conditions.  Some eye conditions can progress slowly without symptoms. Regular eye checkups can help detect changes earlier and make sure you receive appropriate treatment when needed. Step by step: The Process Involved in Having an Eye Examination Even though the different appointments may vary according to your particular needs, a typical full eye examination will involve a number of significant steps. 1. An Examination of Your Medical & Eye History Your appointment may start with questions about your vision, medical history, medications, any previous eye conditions, and your family history of eye disease. Be sure to report any changes in your vision, eye discomfort, headaches, or other concerns you have noticed. Your eye care professional may also ask about the glasses or contact lenses you currently use and how well they work for you. 2. Checking Your Vision A well-known part of an eye examination is the visual acuity test. You might be asked to read some letters or symbols from a chart at a set distance. This lets doctors assess how clearly you can see and decide whether corrective lenses would help. Further testing could assess your ability to see up close and the way well your eyes work together. 3. The Measurement of Eye Health & Function Your eye care professional might carry out a number of tests in order to assess the health and functioning of your eyes. The tests involved may vary depending on your age, symptoms, and risk factors and could include measuring eye pressure, examining eye movement and coordination, and looking at the structures at the front and back of the eye. They can help spot possible signs of eye disorders. 4. Discussing Your Results Your ophthalmologist will review the results with you after the examination. If your vision has changed, they may suggest new prescription lenses. If they spot an eye condition or another issue, they could recommend further testing, further monitoring, or treatment. It is also a good chance to ask questions regarding your eye health and the recommended follow-up care. What Should You do to Get Ready for your First Eye Examination? Having an eye examination usually involves nothing complicated. It is a good idea to take with you your present glasses or contact lens details and to be ready to give a list of any medications as well as any applicable medical or family history. Additionally, it might be helpful to remember any vision changes or symptoms you have had. Dilation may occur during the examination if certain tests are performed. After dilation has been advised, your vision might be temporarily blurred or more sensitive to light. Supporting Healthy Vision The initial eye examination is a valuable chance to determine a baseline for your eye health and understand your specific vision needs. Regular eye exams help monitor changes over time and support early detection of possible eye conditions. Plan a visit with an eye care professional if you have discovered any changes in your vision or if you're due for a check-up.

Children’s Vision Milestones: What Parents Should Watch For

August 28, 2026
Healthy vision is essential for a child's development, learning, and daily activities. From recognizing faces in infancy to reading, participating in sports, and navigating school, children depend on their eyesight to interpret and relate to their environment. Knowing typical vision milestones helps parents spot possible issues and seek appropriate care when needed. How Does Vision Develop in Children? Vision develops rapidly during the first years of life. Newborns perceive light, shapes, and nearby objects, although their vision remains immature. As children mature, their capacity to focus, track moving objects, recognize details, and coordinate both eyes improves progressively. Due to the gradual nature of visual development, regular eye examinations are essential. Certain childhood vision problems may not be readily apparent, especially when one eye is stronger than the other. Although each child develops at an individual pace, several general vision milestones may guide parental observation. 1. Infants: Birth to 12 Months Within the first year, infants typically develop the ability to focus on faces and objects, visually track moving items, and reach for objects they observe. Caregivers may also observe infants responding to known faces and visually exploring their environment. If an infant does not track objects, exhibits eyes that frequently cross or wander, or fails to respond visually to people or objects, these concerns should be discussed with a pediatrician or eye care professional. 2. Toddlers: Ages 1 to 3 As children become more active, their visual skills continue to develop. Toddlers rely on vision to walk, climb, manipulate small objects, and interact with toys. Over time, they typically improve in identifying familiar people and objects and in coordinating eye and hand movements. Frequent eye rubbing, squinting, sitting close to screens, or difficulty seeing objects could indicate the need for an eye exam. 3. Preschool and School-Age Children By preschool and early elementary school, children utilize vision for detailed activities including coloring, drawing, letter recognition, reading, and participating in games. Effective eye coordination and focusing abilities support learning and classroom performance. Children may not always realize their vision differs from other children’s, so parents should watch for signs such as headaches, avoiding reading, losing their place while reading, holding books unusually close, or struggling to see the board. Signs of Possible Vision Problems Caregivers should monitor for changes in a child's vision or behavior. Potential warning signs include: Frequent squinting or eye rubbing Eyes that cross, wander, or do not move together Complaints of blurry or double vision Frequent headaches Difficulty reading or concentrating Sitting very close to a television or screen Tilting or turning the head to see Covering or closing one eye Difficulty recognizing objects or seeing at a distance Avoiding activities that require close or distance vision If you notice these signs, speak with a pediatrician or eye care professional. The Importance of Children’s Eye Exams Regular eye examinations can identify vision problems before they interfere with learning and development. Eye care professionals assess visual acuity, binocular coordination, and common childhood eye conditions. Early detection matters because some vision problems are easier to address when identified in childhood. Parents must follow their child’s healthcare provider's recommendations for vision screenings and comprehensive eye exams. Helping Protect Your Child’s Vision Caregivers can promote healthy vision by encouraging beneficial habits. These include spending time outdoors, taking regular screen breaks, using appropriate protective eyewear during activities, maintaining a balanced diet, and attending recommended pediatric and eye care appointments. Supporting Healthy Vision at Every Age Knowing children's vision milestones helps caregivers distinguish typical development and spot possible issues early. Throughout infancy and the school years, monitoring how a child sees, focuses, and interacts with their environment is vital for supporting healthy development.  If you notice concerns about a child's eyesight or alterations in vision, consult a healthcare provider or eye care professional. Early attention to vision supports learning, development, confidence, and overall quality of life.