Eye Health Central

What To Do About Subconjunctival Haemorrhages

What Are Subconjunctival Haemorrhages?

Subconjunctival Haemorrhages

Although it sounds serious, a subconjunctival haemorrhage is usually not a big deal. Indeed, you might’ve already had a few without even knowing it. When you have a subconjunctival haemorrhage, the blood vessels in the clear conjunctiva break and cause eye redness in the white sclera. While these bloodshot eyes might look serious, they usually clear up on their own within a few weeks.

A subconjunctival haemorrhage is very similar to having a bruise on your skin, but in your eye presents as much redder as it is not under the skin, it may also remain red much longer, before turning, brownish and then yellow, this is because the conjunctiva cannot absorb the leaked blood very quickly

There are, however, a few cases where subconjunctival haemorrhages could signal a serious eye issue. For more information on what causes subconjunctival haemorrhages and when you should seek medical attention, please keep reading.


Causes & Risk Factors For Subconjunctival Haemorrhage

Trauma To The Conjunctiva

There are dozens of potential causes of subconjunctival haemorrhages, but one of the most common is trauma to the eyes. This trauma could be direct or indirect.

  • Direct traumas include an eye injury (especially in high-impact sports) or rubbing your eyes too aggressively. 
  • Indirect causes, on the other hand, include activities like heavy lifting or everyday occurrences like coughing or sneezing. 

Believe it or not, you could also strain your eyes if you suffer from chronic constipation!

People with frequent subconjunctival haemorrhages can also have serious issues with allergies. In these cases, it’s best to work with an allergist to figure out what your triggers are and ways to reduce symptoms.


Daily Blood Thinners

Since ruptured blood vessels cause subconjunctival haemorrhages, it makes sense that blood thinners increase the risk of this disorder. In addition to aspirin, here are a few of the more common anticoagulants that could induce subconjunctival haemorrhages:

• Warfarin
• Apixaban
• Dabigatran
• Rivaroxaban

Also, it’s important to note that a few foods and herbs have a blood-thinning effect on the body. Some of the most common products that naturally cause the blood to thin include:

• Ginger
• Hot chili peppers (e.g. cayenne)
• Garlic
• Turmeric
• Cinnamon
• Grape seed extract

People who are taking anticoagulants might want to talk with a dietician to understand the optimal diet for their condition. Patients prescribed a regimen of blood thinners should also discuss all potential side effects and drug interactions with their doctor.


Eye Surgery Complication

Subconjunctival haemorrhages are one of the most common side effects of any eye surgery. Patients who get regular eye injections also have a higher incidence of subconjunctival haemorrhages compared with the general population.

Be sure to ask your eye doctor about all the potential complications from your surgical procedure beforehand. In most cases, these subconjunctival haemorrhages will fade away on their own within a few weeks.


Preventable Risk Factors: Smoking and Drinking

On average, people who avoid smoking and drinking have fewer episodes of subconjunctival haemorrhages and better overall vision. Of course, illicit drugs like cocaine and heroin have an even more deleterious effect on long-term visual health.

While cannabis is gaining more prominence in the UK for its medicinal uses, it’s important to note that people who frequently smoke marijuana with high amounts of THC are more prone to suffer from subconjunctival haemorrhages. Recent studies have also shown that the popular cannabinoid CBD could have a negative impact on eye health. Patients should discuss all potential side effects of medicinal marijuana and/or CBD oil with their primary care physician.

Anyone who lives in the UK who’s looking for help overcoming smoking or drinking should check out the resources provided on the NHS’s website. For info on the NHS Smokefree program, please click this link. The NHS also has a great deal of information on support for alcoholics on this webpage.


Vitamin K Deficiency

Although it’s extremely rare, some people who suffer frequent subconjunctival haemorrhages could have a problem absorbing vitamin K. In addition to its many other functions, vitamin K is well known for its ability to prevent blood clotting. So, if the conjunctival blood vessels don’t have enough of this vitamin, they are more prone to clot and appear red.

Although subconjunctival haemorrhages could indicate a vitamin K deficiency, it’s highly unlikely they will be the only symptom. Other warning signs of a vitamin K deficiency include easy bruising, severe periods, and blood in the urine.

Doctors can tell whether or not you have a vitamin K deficiency by examining a blood sample. If your tests show abnormally low levels of this vitamin, then your doctor might encourage you to take vitamin K supplements and/or make diet changes.


Dry Eye Syndrome

Red eye is one of the hallmark symptoms of the increasingly common disorder known as dry eye syndrome. If you are a dry eye sufferer, however, then you’ll probably notice more symptoms than just red eyes. Most people who have dry eye syndrome also experience eye itchiness, light sensitivity, and temporary blurred vision.

While not all red eyes caused by dry eye syndrome are subconjunctival haemorrhages, they can look quite distressing. Also, dry eye-related red eye symptoms require the same treatment regimens you’d give to subconjunctival haemorrhages. A few of these treatments include limiting exposure to electronic screens, getting plenty of natural sunlight, and occasionally using eye drops.

Many people with dry eye syndrome have issues with their Meibomian glands, which are essential for producing oils that keep eye tears from evaporating. The only way to know if you have dry eye syndrome, of course, is to discuss your symptoms with a qualified optometrist.


When Should You See An Eye Doctor About Red Eyes?

An occasional red eye is normally nothing to be concerned about. If you have other symptoms and/or your subconjunctival haemorrhages don’t clear up within a few weeks, however, then you might want to visit an optometrist for a professional opinion.

This is especially true if you experience eye pain and pus discharge as well as red eyes. Most often these symptoms are the result of an infection. You should see an optometrist as soon as possible to get the medications you need to clear up this potentially serious disease.


Treatment For Subconjunctival Haemorrhages

As mentioned before, usually you don’t have to do anything to treat subconjunctival haemorrhages. As long as you refrain from rubbing your eyes, this disorder should clear away within about one to three weeks.

To speed up the recovery process, be sure to get plenty of rest and drink a lot of purified water. You might also want to consider making a few dietary changes or trying anti-inflammatory supplements like omega-3 fatty acids.

Allergy sufferers should ask their doctor for medications or strategies for eliminating subconjunctival haemorrhages naturally. Also, anyone taking blood-thinning drugs must talk with their doctor about their subconjunctival haemorrhages if they are becoming an issue.


Ways To Prevent Subconjunctival Haemorrhage

While it’s almost impossible to completely eliminate subconjunctival haemorrhages from our lives, there are a few simple strategies you could put into place to reduce their incidence and severity.


Avoid Rubbing Your Eyes

The simplest thing you could do to improve your visual health is to stop touching your eyes. Every time you rub your eyes you put tremendous stress on the conjunctiva’s fragile blood vessels. Not only will this lead to an increased risk of subconjunctival haemorrhages, it could cause irreversible damage to your cornea. People who frequently rub their eyes are also at a greater risk of developing bags under their eyes and infections.

To get rid of an itch in your eyes, it’s better to apply a few artificial tears than to scratch your eyes. You could also place a clean, wet towel over your eyes to reduce signs of eye redness or itchiness.


Eat A Colourful Diet

Diets that are high in fruits, veggies, and omega-3 rich fish are ideal for overall eye health. People can often notice a difference in their overall eye health and comfort after switching to a more healthful diet.

A few superfoods specifically for the eyes include blueberries, wild-caught salmon, sweet potatoes, sardines, carrots, and lemons. For those who don’t like the taste of fish, consider taking an omega-3 supplement or eating more healthy nuts and seeds like walnuts, Brazil nuts, and chia seeds.

People with recurrent subconjunctival haemorrhages might want to increase their intake of vitamin K rich foods. Leafy greens like kale, spinach, and bok choy are the best sources of this anti-clotting vitamin.


Avoid Staring At Electronic Screens

It’s impossible to go anywhere nowadays without being exposed to blue light from an electronic screen. Research now shows, however, that staring at these screens for too long could do serious damage to our eyes.

To protect your eyes from subconjunctival haemorrhages, try to look 20 feet away from computer screens for 20 seconds about every 20 minutes. By following this 20-20-20 rule you will significantly reduce your risk of developing conditions like dry eye and subconjunctival haemorrhages.

In addition to reducing screen time, it’s also a good idea to increase outdoor time. Spend at least 30 minutes every day walking outdoors in the natural sunlight. If you live in a region where there’s not a great deal of sun, then consider taking a vitamin D3 supplement.


Don’t Be Too Afraid Of Subconjunctival Haemorrhages

Subconjunctival haemorrhages are one of the most common eye disorders, especially in the hi-tech 21st century. In most cases, these unsightly red eyes are nothing to worry about and they will heal on their own if you give them plenty of rest and hydration. Only people who experience subconjunctival haemorrhages frequently and/or are accompanied by painful symptoms should book an appointment with an optometrist. 


Author: John Dreyer Optometrist Bsc(Hons), MCOPTOM, DipCLP
Created: 17 May 2023, Last modified: 15 Feb 2024