What’s Causing my Double Vision? What’s Causing my Double Vision?

Written by David Evans, PhD, MBA   Last modified on August 6, 2018

Have you been experiencing episodes of double vision — seeing multiple images of a single object — and wondering what is behind the issue? Also called diplopia, double vision is often temporary and not related to any serious underlying condition. However it should never be ignored and if it occurs with regularity, you should discuss the occurrences with your eye doctor.

What Causes Diplopia?

Your eyes function independently from one another (for example if you close one eye you can still see out the other) meaning that each eye captures its own set of images that are transmitted to the brain via the optic nerve. Your brain combines these image signals into a single, clear picture with depth perception. Double vision typically reflects a breakdown in this process of combining the duplicate image signals.

It’s important to note that double vision doesn’t necessarily mean that you’ll see two clear images. Oftentimes “double” simply means blurred vision. For example, you may see “ghost” images, which is a type of image blur that causes objects to appear almost transparent because of the image overlay.

When is double vision typically not a cause for concern?

Two of the more common causes of double vision include being tired and drinking alcohol to excess. Eye fatigue is linked with a number of problems beyond double vision, including dry eye, blurred vision, light sensitivity, eye pain and more. As for alcohol, it can impair brain function, leading to a variety of issues including slurred speech and a breakdown of motor function. If you drink alcohol to excess, the impairment of the brain may interfere with its ability to properly combine the two images, which can result in blurred or double vision.

If you experience the occasional bout of double vision tied to either of these aforementioned common scenarios, it’s typically not a cause for concern.

When is double vision a cause for concern?

If you are experiencing regular bouts of diplopia that cannot be attributed to eye fatigue or alcohol, there may be a more serious underlying condition. Some of the more problematic causes of diplopia include:

Cataracts: If you have cataracts, the associated clouding of the lens of cause various vision problems, including double vision. A cataract prevents light entering the eye from being appropriately directed on to the retina. The resulting scattering of light can cause the appearance of ghost images.

Brain Anomaly: An underlying issue with brain function could be signaled by double vision. Brain tumors, swelling and stroke are associated with double vision. If your issues develop suddenly and appear chronic, it could signal an issue sourced in the brain.

Corneal Health: Double vision may result from an issue with the shape and function of the cornea. Keratoconus — a condition marked by thinning of the cornea — and corneal dystrophy — deterioration of the cornea — can cause diplopia.

Dry Eye: You might think that something like dry eye is simply a benign condition that causes irritation of the eyes, but it can also impact your quality of vision. The lack of tear production and lubrication associated with dry eye can cause burning and general discomfort, but it can also cause blurred or double vision.

Refractive Surgery: On rare occasions, double vision can be a side effect associated with refractive surgery. If you’ve recently had LASIK, PRK or another type of refractive procedure, you may experience some short-term blurred or double vision. This issue often goes away by itself over the course of a few weeks, but it could require a secondary surgery to correct it. Refractive surgery patients go through a series of post-surgery evaluations, so any such issues should be discussed during these follow-up visits.

The good news for sufferers of double vision is that there is an array of treatments available. Treatment depends on the root cause, meaning that your eye doctor must first diagnose the cause before recommending an appropriate treatment. Double vision treatments may include surgery, medications, changing of your prescription, vision therapy and more.

For more information on distorted vision, I urge you to check out our 9 causes of blurred or distorted vision slideshow.