Just about everyone has looked in the mirror and seen a pair of red eyes staring back at them. But, what are the most common causes of red eyes, and what can you do about them?

Read on to learn about common causes of red eyes.

Smoke Irritation

If you’re a smoker, you probably have irritated eyes on a regular basis. Smoke can easily lead to red eye, but it can also cause other eye problems. Turns out, smoking has also been linked to an increased risk of cataracts.1

Smoking may also play a role in age-related macular degeneration, or AMD – a condition that can lead to blindness. The good news is, if you quit smoking, your risk of AMD will eventually decrease.2

Contact Lenses

Contact lens issues are among the more typical causes of red eyes.

When you wear contacts for too long, or you don’t clean them properly, they can irritate the surface of your eye.

This makes the blood vessels swell, leading to the dreaded red-eye.3

The best thing you can do to avoid this problem is to make sure you clean your contacts regularly and store them properly. If you have disposable lenses, make sure you throw them away when the directions tell you to do so.

Dry Eye

Causes of Red Eyes | Sight OriginsMore than likely, you’ve experienced dry eyes at some point. This happens when either your eyes can’t produce tears at all, or the tears they do produce aren’t enough to provide good lubrication. In some cases, dry eye can damage the surface of your eye and affect your vision.4

Now, there are a lot of over-the-counter products designed to provide lubrication to the eyes. If you try them and don’t find relief, it’s time to see an eye doctor.

Sleep Deprivation

Turns out, one of the causes of red eyes is a lack of sleep. Have you ever noticed that your eyes turn red when you don’t get enough sleep? This happens because your eyes are retaining fluid.

When your eyes stay open for too long, the fluid inside of them can’t circulate properly. As a matter of fact, some people even sleep with their eyes open all night.5

Looking at the Computer

Staring at a computer screen for hours at a time can lead to some serious eye redness. Staring at a tablet, a television screen, or even your smartphone can also strain your eyes, causing major redness and irritation.6

You can keep from getting bloodshot eyes by taking breaks. Turn away from the screen for about 20 seconds every 20 minutes or so, looking at something at least 20 feet away.7

Also, try to make a conscious decision to blink. You’d be surprised at just how little you blink when you stare at a screen.8


Causes of Red Eyes | Sight OriginsOne of the more common causes of red eyes is some sort of allergic reaction. You might have been outside on a day when there was a lot of pollen in the air, or you could have come into contact with a chemical that caused some sort of irritation.

Some people have allergies to certain foods, and that can lead to irritated eyes. If you wear contacts, the solution you keep them in overnight could cause itchy eyes. The possibilities are almost endless.9

If your eye redness is due to an allergy, talk to your doctor to see if you might need a prescription medication to deal with the problem.

Injury to the Eye

If you hurt your eye, it’s going to turn red. Something as simple as rubbing your eyes when they get a little dust in them can lead to bloodshot eyes. The reason is that the cornea – the surface of the eye – has been irritated.10

Any injury to the eye is a medical emergency. Seek care immediately.


Whenever you have a cold or flu, you’re probably going to have eye redness as well. If your eyes don’t get back to normal after your illness subsides, you should go to the doctor to determine why.

Pink Eye

Pink eye is not only among the more common causes of red eyes, it’s also one of the most frustrating.

Known as conjunctivitis, pink eye is extremely contagious.

Conjunctivitis affects a membrane in your eye known as the conjunctiva. Pink eye irritates your eye’s blood vessels, causing them to swell. The result is often pain, severe irritation, and red eyes.11

Talk to your doctor if you have any reason to suspect you have pink eye. He or she will recommend medication to address the issue, and will also show you how to keep from spreading it to anyone else in your home.


Who would have thought that pregnancy would be listed among the causes of red eyes?

Causes of Red Eyes | Sight OriginsBut the fact is, the hormonal changes that are a part of pregnancy can also affect your eyes, irritating them and making them more sensitive to light.

In some cases, the curvature of a woman’s cornea can slightly change during pregnancy.
If this happens, new contacts or glasses might be needed – at least temporarily.12

Poor Hygiene

Always practice good hygiene, especially when it comes to your eyes. If you don’t take the time to thoroughly wash around your eyes, problems could result.

Improper cleaning around the eyes can make your eyelids oily, leading to severe irritation. This can also make your eyes burn and become itchy to the point where they turn red.13

If you do practice proper hygiene, and you’re still experiencing these problems, see your eye doctor.

Redness in Eyes: Many Causes

As you can see, there are a lot of potential causes of red eyes. Thankfully, most of them aren’t that serious. If you get enough sleep, stop smoking, and practice good hygiene, you can go a long way toward avoiding this problem.

But if you have suffered some sort of eye injury, or if you’ve developed pink eye or redness in the eye and you don’t know why, see an eye doctor. They can determine the cause of the issue and put together the best possible plan to deal with it.

Learn More:
What is Astigmatism? (and can it be corrected?)
Are Cheap Sunglasses Bad for Your Eyes?
The Benefits and Dangers of Blue Light