Red veins in the eyes are often caused by swollen or dilated blood vessels, which can make the surface of the eye look red or bloodshot. There are many causes of red eyes, including:
- Eye dryness
- Too much sun exposure
- Dust or other particles in the eye
- Allergies
- Infection
- Injury
- Uveitis: Inflammation of the uvea, which includes the iris, ciliary body, and choroid. The cause is most often not known. It may be related to an autoimmune disorder, infection, or exposure to toxins. The type of uveitis that causes the worst red eye is called iritis, in which only the iris is inflamed.
- Colds or allergies
- Wearing contact lenses for too long
- Staring at a computer screen for too long without a break
- Conjunctivitis: An infection that includes swelling and irritation of the conjunctiva. The conjunctiva is a thin transparent membrane that lines the inside of the eyelid and loops back to cover the white part of the eye. An infection of the conjunctiva irritates the blood vessels, causing them to swell. This inflammation makes the whites of the eyes appear reddish or pink.
- Subconjunctival hemorrhage: A small amount of blood builds up under the conjunctiva, which is clear, causing bright red spots to appear on the white of the eye. This can result from a minor injury or trauma to the eye, including rubbing the eye due to allergies.
Red eyes alone are not usually a reason for concern. However, if there is also eye pain, watering, dryness, or impaired vision, this can indicate a serious medical problem. Treatment for red eyes depends on the underlying cause and may include artificial tears, antihistamines, or antibiotics.
