Debunking Common Eyesight Myths!

02/10/2020

written by Dr. Jeffrey Lewis, one of the featured ODs in ASCO’s Optometry Gives Me Life campaign www.futureeyedoc.org

Can you think of a common eyesight “fun fact” that you’ve never actually heard a doctor say? Those are what we’d call “eyesight myths” — old wives’ tales for your eyes.

Most of us have probably wondered how true they are. So today, we are going to break down some common eyesight myths and separate fact from fiction, in our first of a three-part series.

Myth 1: You can’t sneeze with your eyes open.

Fact: You actually can sneeze with your eyes open, but your local Doctor of Optometry is going to tell you that this isn’t something you should try and practice. There are a few theories why we naturally close our eyes when we sneeze:

  • The face has many, many muscles. When we sneeze, a lot of the muscles in our faces contract forcefully, with some of those muscles being around the eye, which forces our eyes to also contract.
  • Typically, a sneeze is forcing out irritants or nasty stuff (e.g. upper respiratory infections). Sneezing with our eyes closed may be an evolutionary adaptive protective mechanism to prevent all that nasty stuff our body wants out from going back into our eyes.

Myth 2: We see everything in our field of vision.

Fact: We actually have a blind spot in each eye. It is located at the back of the eye and is called the “optic disk.” This structure is extremely important to our vision. It is responsible for collecting all the fibers (called axons) from the retina and forming the beginning of the optic nerve. The optic nerve then transmits the fibers carrying the visual information from the eye to the brain.

Fortunately, we have two eyes.

The brain is able to process a tremendous amount of data and uses both eyes’ visual cues to fill the gap in our vision without us even knowing.

Most people are also unaware that we see upside down! Impressively, our own personal supercomputers (a.k.a. our brains) are also able to invert the images from the retina so that we can see things right side up.

Myth 3: Color blindness means you can’t see any colors.

Fact: A more appropriate term for “color blindness” is “color vision deficiency.” It’s actually very rare for people labeled as color blind to only see shades of white, gray, or black.

Both men and women can be color blind. Statistically, males are far more likely to be color blind than females.

Interestingly enough, I, Dr. Lewis, have a color vision deficiency. My color blindness is called “Deutan color blindness” (also known as deuteranomaly).

Deuteranomaly is a type of red-green color blindness in which the green cones in the eye detect too much red light and not enough green light. As a result, red, yellow, green, and brown can all appear similar, especially in low light. It’s often very difficult for me to tell the difference between blues and purples or pinks and grays.

There are different types of color blindness, but the red-green color blindness that I have is the most common inherited form of color deficiency.

Some statistics suggest that red-green color blindness make up to 4% of the world’s population, and among the color-blind population, 75% people diagnosed with color blindness have Deutan color blindness like me.

Did you know the truth about these myths before reading? Or was I able to shed some light (ha!) on how our eyes work?

Share this article with someone who doesn’t know that we see upside down! And stay tuned for the next part in our three-part series.

Jeffrey Lewis, O.D.