What causes bloodshot eyes?

We’ve all been there – your eyes suddenly become bloodshot and you look like you’re auditioning for a part as an extra in The Walking Dead. Fear not, it’s not an unusual occurrence and most of the time things look far worse than they are.

Affecting factors

Although the main cause is swelling of the blood vessels, there can be many additional contributing factors. We’ve short-listed the most common, and if you’d like to know more about each one and how you can treat it, read on further below:

• Conjunctivitis
• Eye infections such as blepharitis
• Improper contact lens use
• Eye whitening drops
• Cold and flu
• Smoking, drinking alcohol, and drug use
• Tiredness and dry eyes

Conjunctivitis

One of the top likely causes behind red eyes, conjunctivitis is a condition where the conjunctiva swells and becomes irritated. The conjunctiva is a thin, transparent membrane that covers the outside of the eye and the inside of our eyelids.

You may experience conjunctivitis as a result of an allergic reaction, an infection or from a chemical irritant such as chlorine. It’s a contagious condition, so be sure that you don’t share cosmetics, face towels or pillows. Once the cause is identified, your doctor is likely to prescribe antibiotic eye drops or antihistamines. You can maintain good eyelid hygiene by using a warm, clean cotton wool pad to gently rub your eyelashes to remove any debris.  

Eye infections

Eye infections can cause the blood vessels in the eye to become inflamed. Blepharitis, for example, is where edge of the eyelids become irritated and sore. This can result in redness of the eye, sensitivity to light, and eyelashes falling out. If you feel you are suffering from blepharitis, make sure you practice good hygiene.

Improper contact lens use

If you wear contact lenses, you may suffer from eye redness as a result of not using them properly.

You should wash and dry your hands thoroughly before inserting or removing your contact lenses. If they’re daily disposables, make sure you’re throwing them away at the end of each day and not reusing them. If you’re a wearer of monthly disposable lenses, ensure that the correct cleaning and storing regimen is being followed.

Contact lens thickness is different for every product. The thinner the lens, the more oxygen is able to reach your eye. If the oxygen supply is restricted, it can lead to redness. If you feel like your contact lenses might be causing the problem, check with your optician that you’re wearing the best possible product for you.

Eye whitening drops