'Red eye' is a term used when irritation or infection causes blood vessels on the white of the eye to dilated and look red.
Eye redness can have causes that aren't due to underlying disease. Examples include rubbing eyes, sleep deprivation, prolonged screen time, chlorine (from pools) or smoke exposure.
Other causes dry air, exposure to the sun, dust, allergic reactions, colds, bacterial or viral infections, such as measles, coughing.
Dry eye is a major cause of red eyes. Most red eyes can be treated at home with hot compresses or over the counter medication or lubricants.
If your red eye/eyes lasts longer than a week it is best to seek optometric or medical treatment.
Beware the unilateral red eye
More serious causes of eye redness include infections. Infections can occur in different structures of the eye and typically produce additional symptoms such as pain, discharge, or changes in your vision.
Infections that can cause eye redness include:
- Inflammation of the follicles of the eyelashes, called blepharitis
- Inflammation of the membrane that coats the eye, called conjunctivitis or pink eye
- Ulcers that cover the eye, called corneal ulcers
- Inflammation of the uvea, called uveitis
Other causes of eye redness include but not exhaustive are:
- Trauma or injury to the eye
- A rapid increase in eye pressure that results in pain, called acute glaucoma
- Scratches of the cornea caused by irritants, fingernails, foreign bodies or overuse of contact lenses
- Inflammation of the white part of the eye, called scleritis
- Eyelid styes
- Bleeding problems
- Rheumatoid arthritis (RA)
If you have pain, changes to your vision (blurriness), headache or vomiting, or trauma, then seek an URGENT medical or optometric appointment.