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Red eyes? See an optometrist!

Are your eyes red? Are they irritated and bloodshot?

Your optometrist should be the first person you see when you have red irritated eyes.

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What is a red eye?

Your eyes become red when tiny blood vessels under the eye’s surface get larger or become inflamed. Usually, this occurs when something is irritating your eye.

You may only have one red eye, or both can be affected.

Red eyes are often accompanied by pain, itchiness, a discharge from one or both eyes and your eyes may be swollen. You may also experience a change in your vision, such as blurred vision.

Often, a red eye can look worse than it feels.  However, if your eyes are red for more than a week, or if your vision is affected, or if there is pain, make an appointment with an optometrist.

What causes red eye?

There are many things that can cause a red eye.

It could be that you have been wearing contact lenses for too long or staring at a computer screen for a long time without a break.

Red eyes can also be caused by allergies, blepharitis (inflamed eyelid), conjunctivitis (pink eye), dry eye, eye injury, or glaucoma.

Common causes of red eyes:

Environmental causes of bloodshot eyes include;

  • Airborne allergens
  • Air pollution
  • Smoke, including second-hand cigarette smoke
  • Dry air, including from airconditioned offices, or a plane cabin
  • Dust
  • Chemical exposure, chlorine in swimming pools can cause irritation
  • Overexposure to sunlight


When pollen, pet dander, dust, or certain chemicals found in makeup or contact lens solutions get into a person’s eye or body, their immune system reacts. The body releases histamine to fight off the allergens, which also makes the blood vessels in your eyes get larger and your eyes can become red, watery, and itchy.

Dry eyes

When eyes do not produce enough tears, or produce tears that lack lipids, dry eye is the result.

Tears keep your eyes healthy and comfortable. Dry eye symptoms can include stinging or burning, lots of tears followed by periods of dryness, and sometimes a mucus discharge.

Dry eye can be painful, and your eyes may be red.

Anyone can get dry eye, but its more common in women, especially those who have gone through menopause. As people age, they produce less of the lipid part of tears, which puts them at greater risk for dry eye.


Conjunctivitis happens when the membrane covering the insides of your eyelids and the white part of your eye, called the conjunctiva, becomes inflamed.

It is a very common eye infection and children quite often experience this type of infection.

Conjunctivitis can be caused by allergies, bacteria or a virus. Viral eye infections, the most common, tend to improve on their own, and don’t require prescription medication. Bacterial eye infections require antibiotics. Both types of infection, are extremely contagious and spread easily.

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Subconjunctival haemorrhage

Sometimes, a blood vessel in your eye can break, leaking blood onto the surface of your eye – this is a subconjunctival haemorrhage.

It may look serious, but it often goes away on its own in 1 to 2 weeks.  However, if you have a subconjunctival haemorrhage and your vision changes talk with your optometrist.

This condition can sometimes be caused by:

  • rubbing your eyes too hard
  • intense coughing or sneezing
  • vomiting
  • eye injury

You may be more prone to this condition if you’re taking blood thinners or have diabetes or hypertension.

Eyelid stye

A stye is a blockage of the meibomian gland that causes inflammation. It can affect the outside or inside of your eyelids.

If you have a stye, the edge of your eyelid can become red, swollen, and painful. This area may fill with meibum (due to the blocked gland) and can grow to the size of a pea.


A trauma or an injury to your eye can cause redness. Blood vessels in the eye open to allow more blood to get to the injury site for quicker healing. The open blood vessels are what cause your red eye.

Eye injuries can include scratches to the surface of your eye, puncture wounds, and chemical burns. These eye injuries need immediate medical attention and should be treated as a medical emergency.

Contact lenses

People who wear contact lenses touch their eyes more often which puts them at an increased risk of eye redness. The redness may be from:

  • scratches or scrapes on the cornea
  • eye allergies
  • eye infections
  • corneal ulcers, (resulting from sleeping in contact lenses)
  • dry eyes
  • giant papillary conjunctivitis – where bumps develop under your eyelid
  • contact lens induced acute red eye from wearing contacts overnight

How can you prevent eye redness?

Some eye redness can be prevented by using proper hygiene and avoiding irritants that can cause redness.

You should also:

  • Wash your hands frequently, particularly if you’re exposed to someone who has an eye infection.
  • Remove all makeup from your eyes each day.
  • Don’t wear contact lenses longer than recommended or while swimming.
  • Don’t wear contact lenses overnight.
  • Clean your contact lenses regularly.
  • Avoid activities that can cause eyestrain.
  • Avoid contact with substances that can cause your eyes to become irritated. If exposure does occur, flush out your eye immediately with eyewash or water if eyewash isn’t available.

When should you see the optometrist?

Although red eye can go away on its own, sometimes your red eyes are a symptom of a more serious eye condition or disease.

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If your red eyes are accompanied by eye pain, light sensitivity, swelling, or blurry vision, it is important to make an appointment with an optometrist immediately.

The best and safest way to get rid of red eyes, is to see your optometrist to determine the cause of your bloodshot eyes and receive the most effective treatment options.