Eyes
Red eye
Redness of the white of one or both eyes, often from irritation or a minor infection.
Education and reference only. This explains the common causes of red eye and the warning signs that need urgent help, in plain language — it is not a diagnosis or a substitute for advice from a clinician. If you feel very unwell or are worried, seek medical help.
Quick answer
What is red eye?
A red eye happens when the small blood vessels on the surface of the eye become enlarged, making the white look pink or bloodshot. Most red eyes are caused by harmless and self-limiting problems such as conjunctivitis, dryness or a blocked oil gland on the eyelid.
- Get urgent help: A red eye with pain, reduced vision, or sensitivity to light – a possible uveitis or other serious cause needing urgent eye assessment. A red eye after an injury, or in a contact-lens wearer.
- Self-care: For a red eye that is mildly gritty or sticky without pain or vision changes, gently cleaning the lids with cooled boiled water and a clean cloth, and using lubricating drops from a pharmacy, often helps.
About red eye
A red eye happens when the small blood vessels on the surface of the eye become enlarged, making the white look pink or bloodshot. Most red eyes are caused by harmless and self-limiting problems such as conjunctivitis, dryness or a blocked oil gland on the eyelid. The features that matter most are whether the eye is painful, whether your vision is affected, and whether bright light hurts. A red eye that is simply gritty or sticky is usually minor, but redness with pain, reduced vision or light sensitivity can point to a more serious cause inside the eye and needs prompt assessment.
When to get help
Call 999 or go to A&E if red eye comes with any of these warning signs:
- A red eye with pain, reduced vision, or sensitivity to light – a possible uveitis or other serious cause needing urgent eye assessment.
- A red eye after an injury, or in a contact-lens wearer.
- A very painful red eye with halos around lights and feeling sick – a possible acute glaucoma.
When to see a doctor
See a clinician or optician if a red eye is not settling after a few days, keeps coming back, or is producing a lot of discharge. Get checked the same day if the eye is painful, your vision is affected, bright light is uncomfortable, or you wear contact lenses, as these point to causes that need prompt treatment. A red eye following any injury or a chemical splash should be assessed urgently rather than managed at home.
Not sure how urgent it is? It is always OK to call NHS 111 for advice, day or night.
What can cause it
Common causes of red eye
Red eye has many possible causes. Each links to a full, plain-language guide to that condition — what it is, how it's treated and when to seek help.
What helps
Self-care and what you can do
For a red eye that is mildly gritty or sticky without pain or vision changes, gently cleaning the lids with cooled boiled water and a clean cloth, and using lubricating drops from a pharmacy, often helps. Warm compresses can ease a stye or blocked gland. Avoid wearing contact lenses or eye make-up until the eye has fully settled, and wash your hands well, as some causes of red eye are infectious and easily spread. If the redness comes with pain, reduced vision or strong light sensitivity, do not rely on self-care and get it checked promptly.
Answers
Red eye: frequently asked questions
Is a red eye usually serious?
Most red eyes are caused by minor problems like conjunctivitis or dryness and settle on their own. The warning signs that suggest a more serious cause are pain, reduced vision and sensitivity to light, which mean the eye should be assessed promptly.
Why does a red eye in a contact-lens wearer need checking?
Contact-lens wearers are at higher risk of infections and ulcers on the surface of the eye, which can threaten sight if not treated. A red, uncomfortable eye in a lens wearer should be checked the same day, and you should stop wearing lenses until it has been seen.
How can I treat a mild red eye at home?
For a gritty or sticky red eye without pain or vision changes, clean the lids gently with cooled boiled water, use lubricating drops from a pharmacy, and try warm compresses for a stye. Avoid contact lenses and make-up and wash your hands, as some causes spread easily.
When is a red eye an emergency?
Seek urgent eye assessment for a red eye with pain, reduced vision or light sensitivity, a very painful red eye with halos and nausea, or a red eye after an injury or chemical splash. These can signal serious problems inside the eye that need prompt care.
Sources
Where this is drawn from
- NICE CKS: Red eye.
- RNIB (Royal National Institute of Blind People).
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