What Causes Red Eye?

One of the most common concerns our patients have about their eyes is redness. The reason people get red eyes can vary greatly from person to person. Because of the many causes of red eyes, it can be a frustrating experience. This leads many to ask what causes red eyes?!


One of the main causes of red-eye is allergies. Allergies that affect the eyes may be worse at certain times of year (commonly in the spring) or maybe due to common environmental allergens (dust, dander, etc). The symptoms of allergies that affect the eyes are itchiness, watery eyes and a general redness of the eyes.

Pollen Agitating Eyes Downtown Kelowna
Pollen allergies can trigger allergic reactions, which affect the sinus and respiratory tract of those with this allergy.

Bacterial Infection

Pink eye is a generic term that many people use to describe an eye infection. A more accurate term to describe ‘pink eye’ is conjunctivitis. The conjunctiva is the outermost layer covering the whites of the eyes. Conjunctivitis may be caused by a bacteria or virus and causes this layer to become red and inflamed. Often, conjunctivitis is contagious and should be evaluated by an eye doctor to determine the best treatment. Antibiotics, for example, should only be used if prescribed by an eye doctor who is treating bacterial conjunctivitis. Symptoms of pink eye (or conjunctivitis) may be burning or itchiness, coloured discharge coming from the eyes, sensitivity to light and crusty eyelids or eyelashes (especially in the morning).

Broken Blood Vessel

Another common cause of a red eye is known as a subconjunctival hemorrhage. This is when one or more tiny blood vessels break beneath the surface of your eye. The blood is trapped beneath the clear conjunctiva layer and makes the white of your eye look bright red. It can be caused by straining (for example, heavy lifting) or rubbing your eye a little too hard. Usually, there is no pain and very little symptoms, despite the dramatic appearance of the redness. Although this is generally not concerning and will fade over a period of weeks, it is important to have it checked by an eye doctor.

Dry Eye Disease

Perhaps the most common reason people experience red eyes is dry eye disease (read more on this from the Mayo Clinic here). There are different forms of ‘dry eye’. For example, sometimes the tears your eyes make evaporate too quickly, and other times, there may be an overall lack of tears. There are many symptoms of dry eye disease.

Symptoms of Dry Eye Disease

  • Grittiness of the eye
  • Burning of the eyes
  • Blurry or fluctuating vision
  • Discomfort in contact lenses
  • Paradoxical watery eyes

This provides some general guidelines when it comes to common causes of red eyes. However, the most important thing is to get an eye examination to confirm and properly manage red eyes. This is because there are many more serious causes of red eyes including glaucoma, iritis or even a sight-threatening corneal ulcer, which must be ruled out by your eye doctor.

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Downtown Optometrist Dr. Danny Walker

Dr. Danny Walker hails from Mississauga, Ontario, and has been practicing Optometry in the Okanagan for the past three years. Dr.Walker completed both his Bachelor of Science and Doctor of Optometry degrees at the University of Waterloo. At Inspired Eyes Optometry, Dr. Walker enjoys being able to provide his patients with thorough examinations and personalized eye care. 
Dr. Walker is available for morning, daytime, evening and Saturday appointments at Inspired Eyes Creative Eyewear & Optometry. Call (250) 862-5900 or Book Online.


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