What causes sudden redness and bloodshot eyes?

Sudden redness and congestion of the white part of the eye may be caused by physiological factors or pathological conditions such as allergic conjunctivitis, keratitis, or dacryocystitis.

1. Physiological factors:

This may result from frequent lack of sleep or prolonged reading, or extended use of electronic devices such as smartphones and computers. Overuse of the eyes leads to eye strain, causing dilation and congestion of the ocular capillaries.

2. Pathological factors:

1) Allergic conjunctivitis: The eyes may become irritated by foreign substances such as sand, dust, or chemical agents, or may come into contact with allergens like pollen or animal dander, triggering allergic conjunctivitis. Inflammation of the conjunctiva due to this condition leads to eye redness and congestion.

2) Keratitis: Injury to the cornea, prolonged wearing of contact lenses, or infection by pathogens such as fungi or bacteria may lead to keratitis, resulting in corneal congestion or eye swelling and redness.

3) Dacryocystitis: A narrow or blocked tear duct can cause tears and bacteria to accumulate in the lacrimal sac over time, leading to dacryocystitis. The surrounding ocular tissues become inflamed, resulting in eye congestion.

In addition to the above causes, dry eye syndrome may also be responsible. Timely differential diagnosis is recommended.