Vision Isn’t Just About Seeing 20/20

July 17, 2023

The first and last thing many people know about good eyesight is 20/20 vision.

Contrary to popular understanding, however, having 20/20 vision isn’t the entire story of healthy eyesight. It’s only a tiny fraction; it simply means that you can see something clearly from 20 feet away without glasses. That doesn’t account for a wide range of vision problems unrelated to basic refractive errors, and those are likely to remain undiagnosed and untreated without a comprehensive eye exam.

Symptoms of Undiagnosed Vision Problems

Some eye problems are accompanied by obvious symptoms, like crossed eyes or a lazy eye, but most are a lot more subtle, especially in kids. Young children can’t identify what they’re experiencing as abnormal, so they don’t think to describe the problem to an adult. All they’re aware of is that they can’t seem to perform as well as their peers in school or sports even when they try their hardest. They end up confused, upset, and discouraged, adults around them are often frustrated, and too many of these kids are misdiagnosed with learning disorders while their eye problems remain untreated.

Symptoms of eye problems to watch for include:

  • Difficulty concentrating
  • Struggles with reading comprehension
  • Frequent headaches
  • A short attention span (particularly for close work)
  • Neck strain
  • Double vision
  • Dizziness
  • Frequent blinking and rubbing of the eyes
  • Poor depth perception

The Teamwork of Healthy Eyes

When eyesight works correctly, both eyes are working together. This is called binocular vision. If you want to see how it works, just cover one eye, focus on an object, and then switch eyes. Human eyes aren’t very far apart, but they do see from slightly different angles, and the differences between the two images create a live 3D image that makes it possible for us to judge how far away things are.

Binocular vision can be affected by a variety of problems:

  • If the eyes struggle to turn outward to focus on distant objects, we call it divergence insufficiency. If they turn outward too much, that’s divergence excess.
  • If the eyes turn inward too much to focus on close objects, that’s convergence excess, while turning inward too little to focus on close objects, we call it convergence insufficiency.
  • If one eye turns inward or outward, that’s strabismus.
  • Amblyopia or “lazy eye” is when the brain favors input from a single eye, leading to worsening acuity in the other eye. This can come from a refractive error or strabismus in one eye.
  • Vertical heterophoria is when the eyes are vertically misaligned and strain to create a coherent image together.

Most of these problems with binocular vision dysfunction are treatable with visual therapy or corrective lenses, but they must be diagnosed before they can be treated! Some of them may require surgery to correct.

Comprehensive Eye Exams Change Lives and Futures

The school nurse will give students the big E test, but that can only diagnose nearsightedness. A comprehensive eye exam, however, can test for all the other vision problems we’ve described and more. An undiagnosed vision problem can create ripple effects throughout a child’s entire school career. Many adults today grew up with an undiagnosed vision problem. Make sure to schedule your child for a comprehensive eye exam so that we can catch any eye problems they may have.

The earlier a vision problem is diagnosed, the better!

Top image used under CC0 Public Domain license. Image cropped and modified from original.
The content on this blog is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of qualified health providers with questions you may have regarding medical conditions.