Pink eye, also known as conjunctivitis, is an inflammation of the transparent membrane that lines the eyelid and eyeball, called the conjunctiva. This inflammation causes the small blood vessels in the conjunctiva to become swollen and irritated, making them more visible and giving the whites of the eyes a reddish or pink appearance. Pink eye can affect one or both eyes and can be caused by a variety of factors, including:

• Viral infections: Most cases of pink eye are caused by adenovirus, but it can also be caused by other viruses, including herpes simplex virus and varicella-zoster virus.

• Bacterial infections: Pink eye can also be caused by bacterial infections, such as those that cause strep throat.

• Allergic reactions: Allergic conjunctivitis is a type of pink eye that comes from an allergic reaction to pollen, animals, cigarette smoke, pool chlorine, car fumes, or something else in the environment.

• Foreign objects: A foreign object in the eye can cause pink eye.

• Blocked or incompletely opened tear ducts in babies: This can cause pink eye in infants.

Pink eye is highly contagious and can be spread through close contact with an infected person, touching surfaces contaminated with bacteria or viruses, or through the air by coughing and sneezing. Symptoms of pink eye include redness, swelling, itching, and discharge from the eye. Treatment for pink eye depends on the cause and may include antibiotics, antiviral medication, or antihistamines. It is important to practice good hygiene to prevent the spread of pink eye, such as washing your hands frequently, avoiding touching your eyes, and avoiding close contact with others if you have symptoms.