DOSSIER Reading and Vision: a complex link

When you're an avid reader, you do it for lots of good reasons. On the contrary, people who read very little or not at all find it difficult to understand the interest. This connection with this activity, which for most of us seems natural, is complex. Quite simply because it uses visual perception combined with specific neurological characteristics. And that mastering reading is not as easy as it seems. So, are reading and vision inseparable?

Reading, a new major national cause

Reading is an essential activity. In this, it structures individual culture and consciousness. When it is not controlled, it is akin to a cause of inequality of opportunity. The stakes are therefore clear: reading, in the controlled sense of the term, must be brought up to date. French President Emmanuel Macron made it a new national cause in June 2021.

In France, the readership rate remains high: nearly 86% of the population has read at least one book in the last twelve months. 83% on a paper format, 23% in digital format, when 20% alternate between one and the other. Yet this rate of readers is down (-6 points in 3 years.)

The National Autonomous Union of Orthoptists (SNAO) quickly welcomed President Macron's initiative. “ Remember that without efficient visual health, reading skills will not be properly put in place, or even deteriorate. To read, you must first make sure you look well and see well. Indeed, in the elderly, stopping reading is very often the first sign of visual impairment. Arrest resulting in other cognitive losses (memory, communication, autonomy, etc.). For this, on the occasion of this “Great National Cause”, the SNAO calls for the immediate implementation of the first recommendation of the IGAS/IGESR Report. Launch a national campaign aimed at preventing, detecting and monitoring visual disorders in children, young adults and aging patients ,” said union President Mélanie Ordines.

the reading is logically linked to vision, but we will see that seeing well is not the only prerequisite for quality reading. Focusing solely on defects in visual acuity would not facilitate access to reading for as many people as possible. Above all, smooth and efficient reading requires several elements.

Reading and vision, obvious and complex relationship

Several elements are necessary in order to obtain correct perception for reading: near binocular visual acuity , visual field integrity, contrast sensitivity and oculomotricity . Thus, the term vision must be perceived in a global sense. And the association of reading and vision submitted to this globality. And then there are different reading levels. If the latter were only a matter of visual acuity, it would be enough to see well to read well. A quality reading, called "harmonious", requires attention and concentration capacities which will be linked to the brain.

A harmonious reading requires the realization of micro-saccades in order to follow a line and of saccades and vergences (ability of a lens to deflect light rays) to move to the line next. Scientists also believe that dyslexia disorders could come from oculomotor disorders of micro-saccades .

Convergence issues can also prevent playback. Indeed, it is not uncommon for eye fatigue to set in due to strong convergence. Often this forces the reader to give up reading. The ideal, in this case, is to spend some time outside, certainly not to put yourself in front of a screen.

For an assiduous reader, this is the analysis of syllables, not a word-by-word deciphering that allows for fluent reading. The micro-saccades allow the transition from one syllable to the next. Foveation, the process of searching for and obtaining an image, follows the past micro-saccade to go to the next one. This is the purpose of oculomotricity . This gets better with practice. This is why serious and regular reading improves the level of reading.

Contrast sensitivity is also very important. It has been noticed that people with AMD or cataracts have difficulty reading, especially colored texts or texts printed on a background whose color does not contrast strongly with them.

Visual acuity, not sufficient

And yes, it is not enough to see well to read well! Moreover, it is not enough to simply see. In blind patients, reading in the Braille alphabet develops rapidly. Moreover, in blind patients from birth, it is observed that this reading activates the visual cortex of the brain. Proof, if needed, that reading is not simply a question of visual acuity.

Another example: the case of fast readers. But really very fast. Moreover, speed reading championships are frequently organized. They consist of reading unpublished works of 250 to 500 pages as quickly as possible. The world champion, Frenchman Mohamed Koussa , for the occasion read a 400-page book in…1h25.

https://www.youtube. com/watch?v=Y-SC722KadA&ab_channel=FranceInter

It can read more than 900 words per minute! For information, the national average is around 250 words per minute. For the champion, it is not a question of a gift, but of training. " The basis of speed reading is memorization and, contrary to what we think, the faster we read, the more we remember. Slowly, nothing happens in the head. Quickly, we produce neurotransmitters which allow memorization." His technique? Scanning the sentences rather than reading word by word.

It is therefore the properties of the brain that allow us to improve and make reading more fluid. He must be able to coordinate eye movements with extreme precision. With this in mind, he must be informed of the exact position of the retina in space. This is made possible thanks to proprioception.

Proprioception makes it possible to carry out harmonious saccades in order to bring the gaze where it should rest. This place is nicknamed the "center of gravity of the word." We have six eye muscles that "coordinate these movements with extreme precision." The so-called "proprioceptive" information comes from the eye muscles which indicate to the brain the precise position of the eyeballs.

As we can see, reading and vision have an undeniable link, but there is not exclusive. It is above all the brain, and its astonishing capacity for adaptation, which will allow the practice of this activity. This understanding makes it possible to approach in a different way the difficulties that one can experience when faced with reading. Indeed, once again, we are not all equal because our brains can react in different ways. But whatever it is, it must be stimulated to draw its quintessence. Encouraging reading is therefore also a health mission.