Posted on July 23, 2017
By: Jeffrey Colburn, MD
Double vision, or diplopia, is the symptom of seeing two of the objects that you are looking at. Seeing double all the time can be a very troubling problem for one to deal with. Mostly this occurs with our adult strabismus (eye misalignment) patients as a young child’s brain is usually able to turn off and ignore double vision when their eyes are not lined up together.
It is important to determine if the double vision is from one eye by itself (monocular diplopia) or from the combination of both eyes (binocular diplopia). If you cover either one eye or the other and double vision is still present when looking only through one eye, then monocular diplopia is present. Monocular diplopia is not an eye muscle issue, and could be caused by a variety of things including astigmatism, an irregularity in the cornea or lens, a cataract, or a fold on the retina. This situation can be seen and evaluated by your regular eye doctor to help decide the cause and decide the next step.
On the other hand, if the double vision is present only when both eyes are open and trying to work together, then binocular diplopia is present. This is most likely caused by strabismus from one cause or another. An initial evaluation can still be done by your regular eye doctor, who may refer you to an eye muscle specialist (like us!) if needed. Double vision from strabismus can often be effectively treated by prism glasses, eye muscle surgery, or eye exercises depending on the situation.
Reasons to have your double vision checked out as soon as possible include brand new diplopia symptoms in the last 1-2 weeks, a headache, a new droopy eyelid, a new difference in pupil sizes, or other neurologic symptoms. Call your eye doctor if in doubt. If your situation is concerning for a dangerous situation, you may even get directed straight to the emergency room for evaluation.
Photo originally from Dr. Jonathan Trobe, MD, at the University of Michigan Kellogg Eye Center