20/20 Vision Is Only One Part of Eye Health
20/20 vision is often thought of as perfect eyesight, but it’s really just one part of it.
All it means when someone has 20/20 vision is that they are able to see something clearly from 20 feet away without glasses. They could still be dealing with any number of a wide range of vision problems other than basic refractive errors, all of which are much more likely to remain undiagnosed and untreated.
Do You Have Symptoms of an Undiagnosed Vision Problem?
Some eye problems come with very obvious symptoms, such as lazy eyes or crossed eyes, but most are subtler, particularly in children. Young kids don’t know that what they are experiencing isn’t normal, so it rarely occurs to them to describe it to an adult. All they know is that they are expected to perform at the same level as their peers and that they can’t seem to keep up for some reason. The result is frustrated adults, confused and upset children, and an unfortunate number of misdiagnosed learning disorders.
Symptoms to watch for include:
- Trouble concentrating
- A short attention span (especially for close work)
- Problems with reading concentration
- Frequent headaches
- Neck strain
- Double vision
- Poor depth perception
- Frequent blinking and rubbing of eyes
Eyes Should Work as a Team
For good eyesight, we don’t just need our eyes to work individually. We also need them to work effectively as a team, which is called binocular vision. You can see how it works by closing one eye, then the other, while focusing on the same object. You’ll notice that you see things from a slightly different angle out of each eye. This is due to the distance between your eyes. Our brains combine the two images into a single 3D one, which is how we can judge distances.
A variety of problems can impede binocular vision:
- Divergence insufficiency. The eyes struggle to turn outward to focus on distant objects.
- Divergence excess. The eyes turn outward too much when focusing on distant objects.
- Convergence excess. The eyes turn inward too much when focusing on close objects.
- Convergence insufficiency. The eyes struggle to turn inward to focus on close objects.
- Strabismus. One eye turns inward or outward.
- Amblyopia (“lazy eye”). The brain will favor input from just one eye, making the other worsen in acuity. This is often the result of a severe refractive error in one eye or strabismus.
- Vertical heterophoria. The eyes are vertically misaligned, making them strain to create a coherent image together.
Most forms of binocular vision dysfunction can be treated through visual therapy or corrected with special glasses, but only if they are diagnosed. Some are best corrected with surgery.
The Importance of Comprehensive Eye Exams
School nurses often give students the big E test, but this only helps them diagnose nearsightedness. Only a comprehensive eye exam can test for other vision problems, and it is critical to a child’s education to catch a vision problem early on. Many adults never received a diagnosis and went through all of their years of school struggling to see. If you think you or your child might have an undiagnosed vision problem, don’t hesitate to schedule an eye exam.