Red eyes are a common ocular symptom caused by various factors. According to the World Health Organization (WHO), around 30% of people worldwide suffer from conjunctivitis at some point in their lives, and 50% of adults experience episodes of dry eye, particularly due to the increased use of digital screens. While red eyes are generally benign, they can sometimes indicate a more serious condition.
Causes of Red Eye
Eye redness occurs when the blood vessels in the conjunctiva (the transparent membrane covering the eye) dilate, making the eye red or bloodshot. Here are some of the most common causes:
- Allergies: Around 20% of people suffer from ocular allergies, which are caused by allergens such as pollen, dust, or animal hair. Redness is often accompanied by itching and clear discharge.
- Dry eyes: Dry eyes, which affect around half of adults due to prolonged exposure to screens, cause inflammation of the eye surface, leading to redness and a burning sensation. Dry, air-conditioned environments or prolonged use of contact lenses can also aggravate this condition.
- Conjunctivitis: Conjunctivitis, an inflammation or infection of the conjunctiva, is a frequent cause of redness. It can be viral, bacterial or allergic. Viral cases are particularly contagious, while bacterial conjunctivitis often requires antibiotic treatment.
- Digital eye strain: Prolonged use of digital screens can lead to eye strain, an increasingly common cause of red eyes. According to a study by the American Academy of Ophthalmology (AAO), over 60% of people spend more than six hours a day in front of a screen, leading to symptoms of dry, tired eyes.
- Acute glaucoma: Although rare, sudden, severe redness accompanied by intense pain and blurred vision can signal an acute attack of glaucoma. Every year, around 3 million people are diagnosed with this disease, which can lead to vision loss if not treated promptly.
Associated symptoms
Symptoms of red eyes can vary depending on the cause, but the most common include:
- Visible redness in the white part of the eye (sclera)
- Itching and burning
- Tearing or discharge
- Blurred vision, especially in cases of severe infection or irritation
- A sensation of a foreign body or sand in the eye
If you experience intense pain, sensitivity to light (photophobia), or sudden changes in vision, it's important to consult an eye care professional immediately, as these signs may indicate a serious condition.
Treatments and solutions
Treatment for red eyes depends on the underlying cause:
- Allergies: For eye allergies, antihistamine drops can relieve redness and itching. Cold compresses can also soothe discomfort.
- Dry eyes: Artificial tears are often recommended to rehydrate the ocular surface. Around 90% of dry-eye sufferers see an improvement with regular hydrating drops. Reducing screen time and blinking frequently can also help.
- Conjunctivitis: Treatments vary according to cause. Bacterial conjunctivitis requires antibiotics, while viral forms usually disappear within a week or two. In the case of allergies, antihistamine drops are effective.
- Eye fatigue: Regular breaks using the 20-20-20 rule (looking at an object 20 feet away for 20 seconds every 20 minutes) can reduce fatigue. Adjusting lighting and screen position can also minimize symptoms.
- Glaucoma: An acute attack of glaucoma is a medical emergency. It often requires immediate treatment with medication to lower eye pressure or even surgery to prevent vision loss.
When should you consult an Optometrist?
Although ocular redness is often benign and temporary, it is essential to consult an optometrist if:
- There is persistent redness lasting more than 48 hours
- Redness is accompanied by pain, blurred vision or sensitivity to light
- Redness after eye injury or trauma
- There is unusual discharge, especially if it is yellow or green.
According to the National Eye Institute (NEI), rapid and accurate diagnosis is essential to avoid more serious complications, especially in cases of glaucoma or severe infections.
Red eyes can have many causes, from mild irritation to serious infection. If symptoms persist or are accompanied by pain or vision problems, it's crucial to consult an ophthalmologist. Appropriate treatment can prevent complications and protect your vision.