Overlooking Our Vision

When people think about vision, they usually focus on whether they can see 20/20 or need glasses or contacts to see better. But have you ever been told your vision is “perfect” even though you still don’t feel like you’re seeing clearly?

That’s because 20/20 only refers to eyesight—specifically, the clarity of vision at a distance. It originated with the size of a letter E that most people could see at 20 feet. If you can see what most others see at 20 feet, you have 20/20 vision. If you need to be closer—say, 20 feet to see what others see at 40—you have 20/40 acuity (which is still legal for driving).

But vision is made up of so much more. In fact, there are 17 components of vision needed to accurately take in and respond to the world around us. As Dr. David Cook puts it, vision is how we “use light information [to interact] with [our] environments.”

These components include:

• Central visual acuity

• Eye movement control

• Near/distance focusing (simultaneous and sustained)

• Near/distance alignment (simultaneous and sustained)

• Depth perception

• Peripheral vision

• Color perception

• Fine and gross visual-motor skills

• Visual perceptual field

• Visual integration

Though these are often discussed as separate skills, they are deeply interconnected—weakness in one can impact others.

One of my favorite resources for helping patients understand this is a TEDx Talk by Dr. Cam, a Canadian colleague. Even though it’s over a decade old, the message is just as relevant today: vision is more than just 20/20.