Blood in the eye: Should you be concerned about that red patch?

A sudden red patch on the white of the eye can look dramatic and cause understandable concern. In most cases, this is caused by a subconjunctival haemorrhage, a small bleed beneath the clear surface of the eye. It is usually harmless, painless, and clears up on its own within one to two weeks. While it often occurs without an obvious trigger, common causes include coughing, sneezing, eye rubbing, minor injury, or contact lens use. According to a study published in Clinical Ophthalmology, subconjunctival haemorrhage is typically benign in younger individuals, where local factors are the main cause. In older adults, however, systemic vascular conditions such as high blood pressure, diabetes, and arteriosclerosis are more commonly involved. The study also highlights that if the haemorrhage is recurrent or slow to resolve. Though usually mild, persistent cases should not be ignored.A subconjunctival haemorrhage occurs when a small blood vessel breaks underneath the conjunctiva, the clear tissue that covers the white part of your eye. The conjunctiva doesn’t absorb blood quickly, so the blood gets trapped and appears as a bright red patch on the white of the eye (sclera).It might look like something from a horror film, but it’s usually painless, doesn’t affect your vision, and often clears up on its own within two weeks. In many cases, people don’t even realise it’s there until they see it in the mirror.The main symptom of a subconjunctival haemorrhage is a bright red or dark red patch on the white of the eye. Other common features include:There is usually no sign of injury or trauma to the surrounding area.Subconjunctival haemorrhages are often triggered by a sudden increase in pressure in the blood vessels. Common causes include:Sometimes, there’s no clear cause at all. These cases are called idiopathic, and they’re quite common.While anyone can experience a burst blood vessel in the eye, certain factors can increase the likelihood:Maintaining good overall health and managing chronic conditions can help lower your risk.In the vast majority of cases, a subconjunctival haemorrhage is harmless. It doesn't affect the eye's structure or function and heals naturally over time.However, if the haemorrhage occurs repeatedly or is accompanied by other symptoms, it could be a sign of an underlying health issue, such as high blood pressure or a clotting disorder.Most cases resolve within 7 to 14 days, similar to how a bruise fades on the skin. The redness may change colour, turning yellow or orange, before fully disappearing.No medical treatment is typically required. However, you can support healing and relieve minor irritation with:There’s no need to avoid everyday activities unless your eye is feeling particularly irritated.While most cases are harmless, seek medical advice if:You can’t always prevent a burst blood vessel in the eye, but some simple steps can reduce your risk:Disclaimer: This article is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional before making any changes to your health routine or treatment.Also read | What causes oral cancer: Key risk factors you should know