What causes redness or bloodshot eyes?

Generally, redness in the eyes may be caused by lack of sleep, eye strain, inverted eyelashes, dry eye syndrome, conjunctivitis, or other factors. Patients should promptly visit a reputable medical facility to determine the underlying cause and receive appropriate treatment. Specific analysis is as follows:

1. Lack of Sleep

When sleep is insufficient or of poor quality, the eyes get less rest at night, impairing their natural repair and recovery processes. To maintain normal function, the capillaries in the eyes may dilate to supply more blood and oxygen, potentially leading to visible red blood vessels. Improving sleep quality and ensuring adequate sleep duration are key to alleviating this condition.

2. Eye Strain

Prolonged use of the eyes—especially during extended periods of screen time or close-up visual tasks such as reading—can lead to eye fatigue, reduced focusing ability, and impaired blood circulation, resulting in redness. Avoiding prolonged continuous eye use, taking regular breaks, and performing eye massages can help relieve fatigue and reduce red blood vessels.

3. Inverted Eyelashes (Trichiasis)

Inverted eyelashes refer to an abnormal condition where eyelashes grow inward and touch the eyeball. These misdirected lashes irritate the eye surface, causing blood vessels to dilate and become congested, leading to redness. In such cases, prompt medical attention at a qualified hospital is necessary, often requiring surgical correction to remove or reposition the offending lashes.

4. Dry Eye Syndrome

Dry eye syndrome occurs when the eye surface lacks sufficient lubrication from tears, causing dryness and discomfort. This condition can also lead to blood vessel dilation and congestion, resulting in redness. Patients may use medications as directed by a physician, such as sodium hyaluronate eye drops, compound neostigmine-taurine eye drops, or erythromycin eye ointment.

5. Conjunctivitis

Conjunctivitis is a common eye inflammation that can be caused by bacteria, viruses, allergens, or other irritants. The inflammatory response causes dilation and congestion of the conjunctival blood vessels, leading to red eyes. Treatment may include oral medications prescribed by a doctor, such as levofloxacin hydrochloride tablets, acyclovir tablets, or loratadine tablets, depending on the cause.

In daily life, it is recommended to maintain a positive mindset, avoid spicy, stimulating, and greasy foods, prioritize sufficient rest, and develop healthy lifestyle habits.