Red Eyes: What is red eye?

Medically reviewed by Sharon Copeland on 04 May 2021

Red eyes are a common problem that we experience, brought on by several external factors and aspects of modern living. The reason eyes appear red and distressed is due to blood vessels on the surface of the eyes becoming aggravated and dilated by a bacterial infection or irritation.

Most cases of red eye are painless and make life a bit uncomfortable for a short period of time. However, if your red eye is causing severe pain or doesn't improve after a few days, then you should seek advice from your optician or GP.

Megastar and U2 front man Bono is known for almost always wearing dark shades, but few people may know he wears them to protect his eyes from the intense snaps of paparazzi cameras.

What causes red eyes?

Most cases of red eyes are caused by minor eye conditions typically, however, in cases where red eyes are causing you pain, it may be due to something more severe.

Conjunctivitis often cause painless red eyes. Also referred to as pink eye, conjunctivitis is an eye infection that arises after the conjunctiva in your eyes have become inflamed due to infection, an allergic reaction or a response to an irritant.

Dry eye syndrome can sometimes cause eyes to redden due to their lack of moisture. Over the counter eye drops or artificial tears are used to moisten eyes and ease discomfort and irritation can treat red eye. Both conjunctivitis and dry eye are eye problems that can also cause your eyes to be sensitive to light.

Burst blood vessels or subconjunctival haemorrhage also cause the appearance of red or bloodshot eyes. Tiny blood vessels can burst as a result of straining, sneezing, vomiting or coughing severely and appear as red blotches on the surface of your eye. However, these are not usually anything to worry about and will disappear within a couple of weeks.

Other causes of red eye include blepharitis, trichiasis (ingrowing eyelashes) and eyelid problems.

Red eyes can occur from a subconjunctival hemorrhage, which is when one of the tiny blood vessels within the eye bursts. This is usually not a serious condition and you shouldn't experience any pain or loss of vision, unless its episcleritis, which can present itself like a blood shot eye or haemorrhage.

If your red eyes are causing much pain, this could be down to a more serious eye condition such as uveitis or glaucoma or could be the result of a corneal ulcer or scratch.

These conditions can be harmful to your eyes and sight and should be identified and treated by an optician or GP as soon as possible. Glaucoma, in particular, can pose a more serious threat to your vision if not treated quickly. Blurred vision often accompanies it.

Can allergies cause red eyes?

In addition to various eye conditions, allergies and environmental factors can also cause red eyes.

These include:

• Allergens in the air
• Pollution in the air
• Smoke
• Dust
• Exposure to chemicals
• Dry air
• Sun exposure

Can stress cause red eyes?

Stress can cause small blood vessels in the eye to burst and cause a red patch of the white part of the eye. When this happens, it is called a subconjunctival haemorrhage; however, it can also occur from other medical conditions and eye infections. The body produces adrenaline in response to stress which in turn can lead to tension and dry eyes this then can lead to your eyes becoming red.

Can lack of sleep cause red eyes?

Lack of sleep can cause tired eyes which often appear red and bloodshot due to lack of oxygen reaching the eyes. As a result of the lack of oxygen, blood vessels dilate and create a red appearance.

Symptoms of red eyes

Red eyes are often associated with the following symptoms which accompany most of the eye problems discussed above.

• Irritation
• Blurred vision
• Eye pain
• Light sensitivity
• Dry, itchy or watery eyes
• Discharge

Other cases of red eyes present no other symptoms other than redness.

How to reduce red eyes

As stated, most cases of red eyes will clear up quickly without any treatments; however, it does depend on the cause of your red eyes. So, if they are causing you some pain or don't improve after a short while, make sure to visit your eye doctor or GP to find out the cause.

If this is a regular occurrence, then it’s advisable to seek medical help to find a more long-term solution.

Another valuable tip is to remove your contact lenses. You should temporarily stop wearing your contact lenses while you allow your eyes the time to heal. Ensure that your glasses prescription is up to date before switching to glasses.

Home remedies for red eyes

Here are some home remedies you can use as part of your eye care regime to ease the discomfort and relieve the symptoms:

You can use eye drops for red eyes if the redness is a result of dry eyes. These can help to refresh and soothe your eyes

Apply a warm damp towel to your closed eye and hold it there for around 10 minutes to increase the blood flow to the affected area. Doing this allows your eyes to lubricate themselves, easing discomfort naturally

A cold, damp towel can also be applied in the same way to reduce swelling and itchiness. However, make sure the towel is not too cold, so as not to aggravate your eye.

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