Red or Bloodshot Eyes: Causes, Symptoms, Treatment, and Prevention

What Does Having Red or Bloodshot Eyes Mean?

Having red or bloodshot eyes means many different things, ranging from harmless causes to serious eye conditions. The actual reason the eyes are bloodshot is due to the dilation of small blood vessels that are in the white of the eye which causes the red appearance of the eyes. Another reason eyes become red is due to an eye injury. According to the Mayo Clinic, when the eye is injured, blood vessels in the eye become dilated, bringing the blood and cells to repair and heal the injury.

What is the Difference between Temporary and Chronic Bloodshot Eyes?

The difference between temporary and chronic bloodshot eyes is that temporary bloodshot eyes are only short-term, while chronic bloodshot eyes are long-term and often caused by underlying eye conditions. Temporary bloodshot eyes can occur due to a myriad of causes, such as allergy-related irritation, lack of sleep or minor injuries. Chronic bloodshot eyes are often a consequence of more serious underlying eye conditions such as pink eye, eye infections and even glaucoma. Temporary bloodshot eyes are not often a cause for concern and can often go away on their own, or with the help of remedies such as eye drops. If they are caused due to issues such as lack of sleep or allergies, lifestyle changes such as getting more sleep, or minimising allergy triggers can also help relieve them. Chronic bloodshot eyes will be more persistent. If you do not seem to be relieved after lifestyle fixes or medication such as eye drops, and you experience other symptoms such as watery or crusty eyes, then it is important to seek medical attention immediately.

1. Allergies

A prominent cause of red or bloodshot eyes is an allergic reaction to pollens, moulds, animal dander and dust mites, which are all environmental allergens. According to the NHS, the symptoms of an allergic reaction include red eyes, runny nose, sneezing, coughing and swollen eyes, throat and mouth.

The treatment for allergies is allergy medication, allergy avoidance and immunotherapy. Allergies are not usually painful but a constant irritation. Allergies are not typically something to worry about unless they are causing significant disruptions to day-to-day activities.

2. Pink Eye

Pink eye (conjunctivitis) is an inflammation of the conjunctiva which is a lining covering the white part of the eye. It is caused by the dilation of small blood vessels in the conjunctiva, making the eye appear a pinkish-red colour. The symptoms of pink eye are watery eyes, itchy, irritated and sore eyes, crusting in the eye’s corners and white strings or yellow discharge from the eye.

Pink eye, or conjunctivitis, is treated with antibiotic drops or cream. Pink eye may be painful due to the sore and gritty feeling in the eyes. According to the NHS Inform, this eye condition, while irritating, in most cases does not pose a serious threat to the eye or your health. Learn more about pink eye symptoms and causes.

3. Dry Eyes

Symptoms of dry eyes occur because either the tears in a person’s eyes evaporate too quickly or the eyes are not producing enough tears. The symptoms of dry eyes include sore, burning, red or gritty eyes, watery eyes, blurry vision, eyelids sticking together and glare sensitivity. Dry eyes are treated with tear supplement eye drops, warm compresses and certain supplements such as vitamin A and omega 3.

Dry eyes are sometimes painful due to the symptom of irritated eyes but is managed with eye drops. This eye condition is not usually something to be worried about as it can be treated but if the condition persists, causes serious pain or interferes with daily life, it is advised to see an eye health professional.

4. Broken Blood Vessels

Broken blood vessels, also known as a subconjunctival haemorrhage, is caused by bleeding from a broken or burst blood vessel. These broken blood vessels often heal on their own after 1-2 weeks and can be caused by sneezing, eye rubbing and coughing.

The main symptom of broken blood vessels is the white part of the eye turning red in certain patches. Subconjunctival haemorrhages do not usually require treatment as they will improve on their own. If the person feels some discomfort, they may use eye drops to freshen the eyes. Broken blood vessels are painless and not something to worry about as they are almost always harmless according to NSW Health.

What Environmental Factors Can Trigger Bloodshot Eyes?

Environmental factors that can trigger bloodshot eyes include lack of sleep, the presence of allergy triggers and the weather. Read more about these environmental factors that can trigger bloodshot eyes below.

• Lack of sleep: Lack of sleep can lead to dry or bloodshot eyes. This is because the eyes may produce fewer tears after sleepless nights, leading to less protection from irritation and potentially infection, according to the Sleep Education Organisation. Getting the recommended amount of sleep, which is around 7 to 9 hours, according to the National Institute of Health, is important for maintaining healthy eyes.
• Presence of Allergy Triggers: The presence of allergy triggers can lead to bloodshot eyes. These triggers can include pollen and dust, which can lead to the inflammation of the conjunctiva, causing red eyes, according to the Conlon Eye Institute. 
• Weather: Weather such as dry air, windy conditions and excess sun exposure can be the catalyst for enlarged eye vessels, which can give the appearance of bloodshot eyes, according to the Mount Sinai Organisation.

How do Contact Lenses Contribute to Red or Bloodshot Eyes?

Contact lenses can contribute to red or bloodshot eyes if they are unhygienic, ill-fitting or are overworn. Read more about contact lenses and how they can contribute to red or bloodshot eyes.

• Unhygienic: Unhygienic contact lenses occur when regular cleaning and maintenance are not performed, and this can lead to red or bloodshot eyes.
• Ill-fitting: Ill-fitting contact lenses, notably tighter fitting lenses can lead to reddened, bloodshot eyes. 
• Overworn: Contact lenses that are overworn beyond the recommended amount of time will ultimately lead to reddened, irritated eyes.

1. Eye Pain

Eye pain is a general term for pain felt in, on, around or behind the eye. Eye pain has many different causes which will have different levels of severity depending on the other symptoms involved and where the pain is located.

2. Itching

Itching eyes is a common symptom associated with red eyes and may be caused by allergies, conjunctivitis, dry eyes and blepharitis. Itchy eyes are treated with eye drops as they wash away allergies from the eyeballs. A cold compress is also used to relieve itching symptoms.

3. Eye Discharge

Eye discharge is a combination of oil, mucus, skin cells and other debris that accumulates in the eye corners while asleep. Eye discharge also occurs while awake which may be caused by an eye condition. Red eyes and eye discharge are both symptoms of pink eye, also known as conjunctivitis.

4. Swollen Eyes (Inflammation)

Swollen and inflamed eyes are a symptom of many eye conditions such as hay fever, conjunctivitis, keratitis and chalazia. Swollen eyes are often accompanied by bloodshot eyes when associated with these eye conditions. Swollen eyes, like red eyes, can be treated with a cool compress.

5. Changes in Vision

Changes in vision include blurry vision, double vision, black spots in vision, loss of vision, or cloudy vision. Vision changes occur either in one eye or both and are most often caused by refractive errors. However some changes in vision can be an indication of a serious eye condition. Changes in vision that are accompanied by red or bloodshot eyes, are indications that the person should see a doctor or eye care professional as they could have a serious eye condition. Changes in vision may be connected to red eyes as combined they could be an indication of an autoimmune disorder or severe infections.

1. Take in a lot of Water

Staying hydrated with water is crucial for overall health but also for preventing red eyes. Dehydration causes many symptoms including lack of tear production leading to eyestrain, dry eyes and vision problems. Drinking water benefits the eyes as it helps in the production of tears which are necessary for healthy eyes. Dehydration is one cause of dry eyes and the symptoms include red and bloodshot eyes which is why taking in a lot of water is important for preventing this eye condition.

2. Avoid Having Fans or Other Sources of Air Blowing Directly Over Your Eyelids While You Sleep

To prevent red or bloodshot eyes, avoid having fans or other sources of air blowing directly over your eyelids while you sleep. Having cold air hitting your eyes dries the moisture making them dry and uncomfortable which leads to red eyes. Turning off fans at night where possible will benefit the eyes greatly.

3. Use a Humidifier

A humidifier is a device that adds moisture to the air to prevent dryness and is popular especially when it is cold. Humidifiers benefit the eyes by adding moisture to the air and preventing dry eyes which may come with irritation, itchiness and pain. Humidifiers are beneficial to use at night so you don't wake up with dry eyes in the morning.

4. Keep Artificial Tears Always

To prevent red or bloodshot eyes, people use artificial tears to add and maintain moisture on the surface of the eyeball. Artificial tears are types of eye drops that are purchased in pharmacies and are used to treat dry eyes by lubricating the eyeballs. These eye drops can be purchased without a prescription and are a great benefit for the eyes.

5. Wash Your Hands Often

Washing your hands often is a way to prevent red or bloodshot eyes as it stops bacteria from your hands from transferring to your eye. According to the Centres for Disease Control and Prevention (CDC), to prevent bacteria from spreading you should wash your hands with warm water and soap for at least 20 seconds and avoid touching the eyes with unwashed, dirty hands. Hand washing is extremely important in preventing the spread of conjunctivitis of which symptoms include red eyes. Washing your hands often is an effective way of preventing red or bloodshot eyes.

How do Cold or Hot Compresses Help Relieve Bloodshot Eyes?

Cold compresses are often considered helpful in relieving bloodshot eyes. You should place cool compresses, which usually refer to folded towels soaked in cold water, on your closed eyes a couple of times a day, according to the American Academy of Ophthalmology. Hot compresses are more commonly known for relieving dry eyes, however, this can also extend to bloodshot eyes. Like cold compresses, hot compresses refer to folded towels that have been soaked in warm water.

What are the Other Medical Causes of Red or Bloodshot Eyes?

Other medical causes of red or bloodshot eyes include uveitis, blepharitis, an eye injury, scleritis and styes.

These other causes and their definitions are listed below.

• Uveitis: Uveitis is caused by the inflammation of the eye’s uvea which is the middle layer of the eye.
• Blepharitis: This eye condition affects the oil glands in the inner eyelid that touches the eye and causes irritated, gritty and red eyes. 
• Eye Injury: An eye injury oftentimes causes red eyes as when the eye is injured, the blood vessels dilate and cause redness. 
• Scleritis: Scleritis occurs when the white part of the eye called the sclera is inflamed, which may cause severe pain.
• Styes: A stye, also known as an external hordeolum, is a bacterial infection that causes the gland on the eye to swell painfully.

What Complications Can Occur if Bloodshot Eyes are Left Untreated?

Certain complications can arise if bloodshot eyes are left untreated. Red eyes may not always be a sign of a more serious condition, however if your eye redness lasts longer than 1-2 days or if a young child has red eyes, you should seek medical attention, according to the Cleveland Clinic. Prolonged bloodshot eyes may be a sign of something more serious like glaucoma which, if left untreated can lead to vision loss.

What are the Signs that Red or Bloodshot Eyes Need Medical Attention?

There are multiple signs that red or bloodshot eyes need medical attention such as you cannot open your eyes, you have severe pain or have recently had eye surgery or an eye infection. These signs and their definitions are listed below.

• Cannot open eyes: If you are unable to open your eyes because they hurt too much, the lids are swollen shut or they seem paralysed, seek medical attention immediately.
• Very painful: If you are experiencing severe eye pain that is causing nausea, vomiting and headaches, it is important to see a doctor.
• Recently had eye surgery or an eye infection: Redness that does not go away after eye surgery or infection is a concern and should be seen to by a doctor or eye care professional.

How does Lack of Sleep Contribute to Bloodshot Eyes?

Lack of sleep can contribute to bloodshot eyes as it can cause the blood vessels in the eyes to overfill, resulting in bloodshot-looking eyes, according to Better View. Ensure you get a good 7-9 hours of sleep each night to combat this. Some ways to improve the quality of your sleep are to avoid using electronic devices before bed, exercise regularly, and avoid consuming sugar, caffeine or nicotine before bedtime.

Can you Treat Red or Bloodshot Eyes at Home?

At Oscar Wylee, we recommend that if you have red eyes, that you first consult with an optometrist before you try treating it at home. You may treat bloodshot eyes at home, under the guidance of an optometrist, with eye drops and cool compresses and by washing your hands and cleaning bedding regularly.