While you’re reading this it may feel as if your eyes are moving in a linear way across the page, smooth as silk. In fact this is not the case.

What is actually happening is that your eyes are making little jumps from one group of words to the next. These miniscule shifts are known as saccades, and are one of the most delicate muscle-movements that we make.

It is very easy for the effectiveness of these movements to be compromised due to the complex feedback loop which takes place between your extra-ocular eye muscles (which generate the saccades) and the cerebellum (located at the base of your skull). When this loop is weak, it can cause you to grow easily fatigued when reading, to skip words, or even to jump lines of text.

wikipedia.com

The solution is to exercise the feedback loop until it improves enough to eliminate the problem.  A simple set of eye exercises for 10 days is usually enough to get things looking a lot different (pun intended!). Another short-term solution to eye-tracking difficulty is to use some form of highlighter or line guide so that you can more accurately move from one word to the next. This minimises the sensation of losing your place on the page or screen.

Eye-tracking issues can be a hidden problem in children who are struggling to read, but they also surface in another population – astronauts! Being away from gravity for a long duration can affect balance and eye-coordination substantially. As a result, astronauts regularly complete exercises like this when returning from space, as a way of reintegrating them with their “heavier” environment. Indeed, upon their return to earth they are often unable to read at all until this is done. You can get more information on these exercises here.