What Causes Double Vision?

There are a lot of different things that can make your vision look doubled, blurry, or shadowy. Sometimes it's something going on with the surface of your eye - like dryness. If you wear contacts, your lens could also be moving around or not sitting correctly.

Double vision, which is called diplopia, can also happen when your eyes aren't working together the way they normally do. Some causes of double vision are more serious than others, but new or unexplained double vision is definitely something you want to pay attention to.

What Does Double Vision Typically Present As?

Sometimes double vision is much more subtle than fully seeing two of an object right next to each other. Letters may have a faint copy underneath them. Maybe lights look doubled when you're driving at night. An image may look mostly normal, but there's a second, slightly faded version sitting next to it. One important factor to figure out is whether you're experiencing monocular or binocular double vision.

Monocular and Binocular Double Vision

You're staring at a word on your computer and start seeing two of it.

Cover your left eye.

Still seeing two?

Now cover your right eye.

If the double vision is still there when you're looking through one particular eye, that's called monocular double vision.

If everything looks normal when either eye is covered but becomes doubled again when you open both eyes, that's called binocular double vision. Binocular double vision can happen when your two eyes aren't lining up well enough for your brain to turn what they're seeing into one image. Monocular double vision tends to point more toward something happening within one individual eye.

Can Contact Lenses Cause Double Vision?

A contact that is dry, dirty, damaged, moving around too much, or simply not sitting correctly on your eye can make your vision look blurry, distorted, or even a little doubled.

Let's say your contacts looked completely normal when you put them in that morning.

A few hours later, you've been staring at your computer all day and suddenly the words on your screen have a slight shadow behind them.

You blink a few times and they look normal again.

Then it happens again ten minutes later. 

That may not necessarily be true double vision. Something as simple as your contact drying out can make your vision fluctuate throughout the day.

Dry Eyes Can Make Your Vision Look Weird

Dry eyes can affect your vision more than you might expect, especially when you're wearing contacts.

Your contacts sit on the tear film covering your eyes. When that tear film isn't staying smooth and stable, your vision may start looking blurry, or hazy.

You may notice it more toward the end of the day, after you've spent hours looking at a screen, when you're sitting directly under an air conditioner, or even when you're traveling somewhere with really dry air.

Sometimes blinking temporarily makes everything look clear again because you're spreading your tear film back across your eye.

If this happens every once in a while, you might just be having a particularly dry contact lens day. However, if your contacts are constantly getting uncomfortable or your vision regularly starts changing throughout the day, talk to your eye doctor about it.

There are tons of different daily contact lenses, bi-weekly contact lenses, and monthly contact lenses available, and the lens that works perfectly for someone else's eyes may not necessarily be the best one for yours.

Your Contact Could Be Moving Around

Your contact isn't supposed to stay completely frozen in one spot on your eye. A little movement when you blink is normal.

Although, if it's moving around too much, that's a different story.

You might be reading something perfectly clearly, blink, and suddenly the words look blurry. Then the contact settles back into position and everything looks normal again.

If that keeps happening, the lens may not be fitting your eye correctly. If you're constantly blinking to get your vision back into focus, mention it at your next eye appointment.

Astigmatism Can Cause Blurry Vision

If you have astigmatism, your eye doctor may prescribe toric contact lenses.

Toric contacts have to stay oriented correctly on your eye for your prescription to line up where it's supposed to. If the contact rotates when you blink, your vision can temporarily look blurry or distorted until the lens settles back into position.

So, if you wear contacts for astigmatism and notice that your vision seems to go in and out of focus throughout the day, your contact may be rotating.

There are also daily contacts for astigmatism, bi-weekly options, and monthly toric lenses, so your eye doctor can help determine which design and replacement schedule works best for your eyes.

Your Prescription Could Have Changed

Sometimes there isn't anything wrong with your contacts themselves. Your prescription may just not be quite right anymore. Your vision can change over time, and continuing to wear an outdated prescription can leave things looking blurry or distorted.

It's also important to remember that a glasses prescription and a contact lens prescription aren't interchangeable. Contacts sit directly on your eyes, so a contact lens prescription includes information that isn't necessarily included in your glasses prescription.

If you're ordering contacts online, you'll still need a valid contact lens prescription for the lenses you're purchasing.

Cataracts Can Sometimes Cause Double Vision in One Eye

Your contact lens sits on the surface of your eye. Anatomically, you also have a "lens" inside your eye.

A cataract happens when that natural lens becomes cloudy. That can cause hazy or blurry vision, glare around lights, and sometimes double vision in one eye.

If your vision is still doubled after you've taken your contacts out. It's worth having your eyes checked to figure out what's actually going on.

What About Multifocal Contacts?

If you wear multifocal contact lenses, your vision may feel a little different than it did when you wore regular contacts.

Multifocal contacts are designed to give you vision at different distances within the same contact lens. Because of the way they work, some people notice halos, glare, or slightly softer vision, especially while they're first adjusting to them.

If the problem persists after you feel like you've otherwise gotten used to your multifocal contact lenses, reach out to your eye doctor.

What Should You Do If You're Seeing Double With Contacts In?

Take your contacts out. If you're wearing daily contacts, throw that pair away and switch to your glasses.

If you're wearing reusable contacts, take a look at the lens. It could be dirty, damaged, inside out, or dried out. However, don't ever rinse it under the faucet to try to fix it. Tap water shouldn't be used to clean contact lenses.

Then pay attention to what your vision does without the contacts in. If everything goes completely back to normal, your contacts may have been contributing to what you were seeing. If you're still seeing double after you've taken them out, or the double vision keeps coming back, contact your eye doctor.

When Is Double Vision More Serious?

New or unexplained double vision is something you should get checked rather than assuming it's just your contacts.

This is especially important if the double vision comes on suddenly or happens along with a severe headache, weakness or numbness, facial drooping, trouble speaking, confusion, dizziness, trouble walking, severe eye pain, or after a head injury.

Those symptoms can sometimes be a sign of something more serious and may require emergency medical attention.

And if you're currently seeing double, don't drive yourself somewhere. Double vision can make it really difficult to accurately judge where cars, pedestrians, lanes, and other objects actually are. Have someone take you to your eye doctor or the emergency room, or call 911 if you're having symptoms that could be an emergency.

FAQ

Can contacts cause double vision?

A dry, dirty, damaged, poorly fitting, or unstable contact lens can make your vision look blurry, distorted, hazy, or sometimes doubled. Take your contacts out and see whether your normal vision returns. If you're still seeing double without your contacts in, contact your eye doctor.

Can dry eyes cause double vision?

Dry eyes can make your vision blurry or hazy, especially if your vision temporarily clears when you blink. If you're experiencing persistent or true double vision, though, don't automatically assume dryness is causing it.

Can astigmatism cause double vision?

Astigmatism can cause blurry, distorted, or hazy vision that may sometimes look like double vision. If you wear toric contacts, the contact rotating on your eye can also temporarily make your vision blurry.

Why am I seeing double in one eye?

Double vision that remains when you're only looking through one eye is called monocular double vision. There are several possible causes involving the eye itself, so new or persistent monocular double vision should be evaluated by an eye doctor.

Why am I seeing double with both eyes open?

If you see double with both eyes open but the double vision disappears when you cover either eye, you're experiencing binocular double vision. This generally happens when your eyes aren't aligning well enough for your brain to combine what each eye is seeing into one image.

Why does my vision look doubled until I blink?

If blinking temporarily clears your vision, your tear film or contact lens could be contributing to the problem. Dryness can make vision fluctuate, and a contact that moves when you blink can temporarily affect your focus. Our guide on why contacts get blurry when you blink goes into this in more detail.

Should I take my contacts out if I'm seeing double?

Yes. If your vision suddenly seems wrong while you're wearing contacts, take them out and switch to your glasses. If your vision doesn't return to normal or the double vision keeps happening, contact your eye doctor.

When should I worry about double vision?

New, unexplained, persistent, or recurring double vision should be medically evaluated. Sudden double vision can be more urgent, especially if it happens alongside neurological symptoms, severe headache, eye pain, or after a head injury.