Double vision is a common symptom of myasthenia gravis, a chronic condition that causes muscles to grow tired easily. Having double vision can be deeply frustrating and get in the way of daily activities and favorite pastimes. But if you or someone you care for has periods of double vision caused by myasthenia gravis, there are a number of things you can do to help.
What Causes Double Vision in Myasthenia Gravis?
Myasthenia gravis causes your body to mistakenly attack the links between nerves and muscles. This affects the tiny muscles that work in sync to keep your eyes properly aligned. As the muscles weaken, your eyes tend to get out of alignment. This leads to double vision or seeing two images when you look at an object. Myasthenia gravis may also cause your eyelids to droop, which can block your vision. You might also be bothered by bright light.
If you have double vision and other visual symptoms caused by myasthenia gravis, you may notice that they get better or worse from day to day. You might be more likely to see double images later in the evening or after you’ve been reading or using your eyes intensely for a long period.
Double vision and other sight problems are the first symptoms for about half of people who get myasthenia gravis. Roughly 85% of them will also have muscle weakness in other body parts. This is known as generalized myasthenia gravis. The rest will only have visual symptoms, a condition called ocular myasthenia gravis. Men appear to be more likely than women to develop ocular myasthenia gravis.
Tips for Living With Double Vision
Bouts of double vision and other visual problems associated with myasthenia gravis can prevent you from enjoying some of life’s simple pleasures. Driving a car, reading a book or your computer screen, and watching your favorite TV show can become a challenge, if not impossible at times. Fortunately, in addition to medication your doctor prescribes for myasthenia gravis, there are steps you can take and assistive devices you can use. Together they can help you manage double vision and related visual problems. These include:
- Rest. Give your eyes a break by closing them for a few minutes. This often helps relieve double vision, at least for a short time.
- Eye prisms. If you wear glasses, an eye doctor can add a device called a Fresnel prism to one or both of your lenses to clear up double vision. A Fresnel prism is a flexible sheet that’s cut to the shape of an eyeglasses lens and pressed on to the surface of the lens. Prisms bend light, which can cause images to align better and relieve double vision. If you decide to try a prism, be patient. It can take some trial and error, and several months, before it works. It’s more likely to help if your double vision is mild or moderate. Note: Not all doctors believe Fresnel prisms help.
- Eye patches. Covering one eye with a patch when you read, use a computer, or watch TV can prevent double vision. Switch the patch from one eye to the other. If you wear glasses, cover one lens with tape.
- Special contact lenses. Instead of an eye patch, you may be able to get a special contact lens with a darkened center. This can prevent you from seeing double while preserving your side vision.
- Large print books and reading alternatives. Books with large type may be easier to read. You can also purchase print-enlargement devices and software that magnifies your screen. Audiobooks, which you can download to a smartphone or tablet, are another option.
- Glare filters. If bright light makes your double vision worse, get a glare filter for your computer screen.