Allergies or infections, like pink eye, both cause redness around the eye area, says AllAboutVision. If there is redness in the white of the eye itself, it may be due to broken blood vessels, reports the Mayo Clinic.
Allergies occur when something irritates the eye, like pet dander, says AllAboutVision. Some allergies are seasonal, due to pollen from trees and flowers. Other allergies are due to mold or dust mites, and occur throughout the year, whenever the allergen is present. Eye allergies frequently cause redness around the eyes as well as other symptoms, such as swelling or itchiness.
Pink eye, or conjunctivitis, is inflammation that affects the membrane lining the eye and eyelid, according to WebMD. Pink eye is sometimes due to chemical fumes, dryness or allergies. It is also often caused by a viral or bacterial infection. Conjunctivitis due to infection is contagious and presents with symptoms like redness around and in the eyes, swelling, burning, tearing and discharge.
When the small blood vessels just below the eye surface break, they cause bright red regions in the white of the eye, says the Mayo Clinic. This is a subconjunctival hemorrhage, which is usually painless and harmless. The cause is typically a hard cough or sneeze, and the hemorrhage clears on its own with time.