Convergence insufficiency (CI) is an eye disorder where your eyes don’t move at the same time. If you have this condition, one or both eyes move outward when you look at a nearby object.
This can cause eyestrain, headaches, or vision problems like blurred or double vision. It also makes it hard to read and focus.
Convergence insufficiency is most common in young adults, but it can affect people of all ages. Somewhere between 2 and 13 percent of adults and children in the United States have it.
Usually, convergence insufficiency can be corrected with visual exercises. You can also wear special glasses to temporarily help your symptoms.
Your brain controls all your eye movements. When you look at a nearby object, your eyes move inward to focus on it. This coordinated movement is called convergence. It helps you do close work like reading or using a phone.
Convergence insufficiency is a problem with this movement. The condition causes one or both eyes to drift outward when you look at something close by.
Doctors don’t know what causes convergence insufficiency. However, it’s associated with conditions that affect the brain.
These may include:
- traumatic brain injury
- Parkinson’s disease
- Alzheimer’s disease
- Graves’ disease
- myasthenia gravis
Convergence insufficiency appears to run in families. If you have a relative with convergence insufficiency, you’re more likely to have it, too.
Your risk is also higher if you use the computer for long periods of time.
Symptoms are different for every person. Some people don’t have any symptoms.
If you do have symptoms, they’ll occur when you read or do close work. You might notice:
- Eyestrain. Your eyes may feel irritated, sore, or tired.
- Vision problems. When your eyes don’t move together, you might see double. Things may look blurry.
- Squinting one eye. If you have convergence insufficiency, closing one eye might help you see a single image.
- Headaches. Eyestrain and vision issues can make your head hurt. It may also cause dizziness and motion sickness.
- Difficulty reading. When you read, it might seem like words are moving around. Children might have a hard time learning how to read.
- Trouble concentrating. It can be difficult to focus and pay attention. In school, children may do work slowly or avoid reading, which can affect learning.
To compensate for vision problems, the brain might ignore one eye. This is called vision suppression.
Vision suppression stops you from seeing double, but it doesn’t fix the problem. It can also decrease distance judgement, coordination, and sports performance.
It’s common for convergence insufficiency to go undiagnosed. That’s because you can have normal vision with the condition, so you can pass a normal eye chart exam. Plus, school-based eye exams aren’t enough to diagnose convergence insufficiency in children.
You’ll need a comprehensive eye exam instead. An ophthalmologist, optometrist, or orthoptist can diagnose convergence insufficiency.
Visit one of these doctors if you are experiencing reading or visual problems. Your child should also see an eye doctor if they’re struggling with schoolwork.
At your appointment, your doctor will do different tests. They might:
- Ask about your medical history. This helps your doctor understand your symptoms.
- Perform a full eye exam. Your doctor will check how your eyes move separately and together.
- Measure near point of convergence. Near point convergence is the distance you can use both eyes without seeing double. To measure it, your doctor will slowly move a penlight or printed card toward your nose until you see double or an eye moves outward.
- Determine positive fusional vergence. You’ll look through a prism lens and read letters on a chart. Your doctor will note when you see double.
Typically, if you don’t have any symptoms, you won’t need treatment. If you do have symptoms, various treatments can improve or eliminate the problem. They work by increasing eye convergence.
The best type of treatment depends on your age, preferences, and access to a doctor’s office. Treatments include:
Pencil pushups are usually the first line of treatment for convergence insufficiency. You can do these exercises at home. They help convergence ability by reducing near point of convergence.
To do pencil pushups, hold a pencil at arm’s length. Focus on the pencil until you see a single image. Next, slowly bring it toward your nose until you see double.
Typically, the exercise is done for 15 minutes every day, at least 5 days a week.
Pencil pushups don’t work as well as in-office therapy, but they are a no-cost exercise you can conveniently do at home. Pencil pushups work best when they’re done with in-office exercises.
This treatment is done with your doctor at their office. With your doctor’s guidance, you’ll do visual exercises designed to help your eyes work together. Each session is 60 minutes and is repeated once or twice a week.
In children and young adults, in-office therapy works better than home exercises. Its effectiveness is less consistent in adults. Often, doctors prescribe both in-office and home exercises. This combination is the most effective treatment for convergence insufficiency.
Prism eyeglasses are used to reduce double vision. The prisms work by bending light, which forces you to see a single image.
This treatment won’t correct convergence insufficiency. It’s a temporary fix and less effective than other options.
Computer vision therapy
You can do eye exercises on the computer. This requires a special program that can be used on a home computer.
These exercises improve convergence ability by making the eyes focus. When you’re done, you can print the results to show your doctor.
Generally, computer vision therapy is more effective than other home exercises. Computer exercises are also game-like, so they can be fun for kids and teens.
If vision therapy doesn’t work, your doctor might recommend surgery on your eye muscles.
Surgery is a rare treatment for convergence insufficiency. It sometimes leads to complications like esotropia, which occurs when one or both eyes turn inward.
If you have convergence insufficiency, your eyes don’t move together when you look at something nearby. Instead, one or both eyes drift outward. You might experience eyestrain, reading difficulties, or vision problems like double or blurred vision.
This condition can’t be diagnosed with a normal eye chart. So, if you have trouble reading or doing close work, visit an eye doctor. They’ll do a full eye exam and check how your eyes move.
With your doctor’s help, convergence insufficiency can be fixed with visual exercises. Be sure to tell your doctor if you develop new or worse symptoms.