Common causes of a painful red eye

If your red eye is painful or you have other symptoms such asreduced vision, the cause is likely to be one of the below conditions.

These conditions can sometimes be serious and could threaten your sight, so they should be assessed by a doctor as soon as possible.


Iritis is inflammation of the iris (the coloured part of the eye). It's also known as anterior uveitis .

As well asa red eye, you may notice that youreye is sensitive to light, your vision is blurred and you have aheadache.

Often, no cause is identified, although iritis cansometimes be caused by an underlying problem with the immune systemoran infection.

Iritis usually responds quickly to treatment with steroid medication to reduce the inflammation. It rarely leads to severe problems.

Acute glaucoma

Acute glaucoma is a serious conditionwhere there is a sudden increase in pressure inside your eye.Your eye will probably be severely red and painful, and you may feel sick and see halos around lights. Your vision may be blurred or cloudy.

If your GP thinks you may have acute glaucoma, they will refer you to an eye specialist (ophthalmologist) immediately, because the conditioncould potentially lead to permanent loss of vision if it's not treated quickly.

Corneal ulcer (ulcer on the cornea)

An ulcer on the cornea (the clear outer layer at the front of the eyeball)is usually caused by a bacterial or viral infection. It can cause the eye to become red and sensitive to light,andit can feel like there's something in your eye.

Bacterial corneal ulcers are usually seen in people who wear contact lenses. Viral corneal ulcers are often seen in people who frequently get cold sores .

If your GP thinks you have a corneal ulcer, they will refer you to an eye specialist for treatment.

A scratch to the cornea or particle in the eye

A red and painful eye can sometimes be caused by a particle, such asa piece of grit, getting in your eye.

If there's something in your eye, your GP or a hospital doctor at an accident and emergency (A&E) departmentwill try to remove it. They will first put anaesthetic eye drops into your eye to numb it andreduce any pain.

If the particle has scratched your eye, it may feel a bit uncomfortable when the anaesthetic eye drops have worn off. You may be given antibiotic eye drops or ointment to use for a few days to reduce the risk of infection while it heals.


Content supplied by the NHS Website

Medically Reviewed by a doctor on 21 Dec 2018