Special studies have been conducted, concluding that 2/3 of the population is right-eye dominant, while the remainder falls under left-eye dominance. A human typically has two hands, two legs, two eyes, and two brain hemispheres. However, this only reflects the initial observation that humanity is a symmetrical species.
Firstly, we have one dominant hand—predominantly the right hand. Next, we also possess a “dominant” eye. Furthermore, the two brain hemispheres function asymmetrically: the left hemisphere (usually in right-handed individuals) processes logical and abstract thinking and a larger portion handling language; the right hemisphere aids in visual perception.
Returning to the issue of eye dominance, special studies have been conducted and concluded that 2/3 of individuals are right-eye dominant, while the rest are left-eye dominant.
A pertinent question arises: do these unique differences affect the cognitive processing of displayed information, such as text perception? And if so, does it pertain more to left-eye or right-eye dominance? The Cognitive Neuroscience Institute at the Modern University for the Humanities has conducted several investigations to address this question.
The research was conducted on right-handed students, but a small number of participants were also right-eye dominant, with the rest being left-eye dominant.
All participants in the experiment were asked to read a paragraph displayed on a computer screen, which would shift to the left or right side of the screen, while their heads were kept straight towards the center of the screen (under these conditions, the information displayed on the left visual field would be processed by the right hemisphere of the brain, and vice versa).
The results revealed that left-eye dominant individuals could read text faster when the text was shifted from the left to the right side of the computer screen. For the few remaining right-eye dominant individuals, these changes were not significant.
A more detailed analysis demonstrated that when left-eye dominant individuals read text on the left side, their brains processed more symbols compared to reading text on the right side.
In other words, in the left visual field, a fixation is characterized by a higher “information capacity.” This is directly related to reading speed: when a fixation recognizes more symbols, it allows the individual to read faster.
Another indicator of successful reading efficiency is that while processing text, the gaze often glances back at the previously read text (clearly due to perceptual difficulty). Therefore, when reading text on the left side, left-eye dominant individuals glance back less frequently compared to when they read text on the right side.
This indicates that the cognitive ability to process text on the left is superior. Additionally, the vast majority of left-eye dominant individuals tend to have quicker eye movements (known in English as Saccades) towards the left compared to the right.
As all participants in the study were right-handed, their right hand’s control was managed by the left hemisphere of the brain. For right-eye dominant individuals, the same left hemisphere also controlled their right eye movements.
In contrast, for left-eye dominant individuals, the left eye is controlled by the right hemisphere, which typically does not influence the control of movements in their dominant hand. This results in better outcomes. Thus, left-eye dominant individuals can read text on the left side faster.
This information will help consider the issue of eye dominance when producing visual products—such as training programs. Future production processes for left-eye dominant individuals may also be taken into account.
Bui Thanh
