You are a vision virtuoso. This most likely has not always been evident to you nor has it always been appreciated by others. An early researcher at MIT so undervalued vision that he assigned it as a summer research project to a grad student as a preliminary exercize for a more challenging incursion into human and artificial intelligence. Now, several decades later and counting, literally thousands of researchers have built careers around the study of vision. Two of them (Hubel and Wiesel) won a Nobel Prize in Physiology or Medicine in 1981 for their discoveries of vision development.
We are all familiar with vision illusions which seemingly trick our eyes into seeing things that are impossible. (See link at bottom for vision illusions) This suggests that vision fabricates, but that sometimes it fabricates without tethering itself to reality. Perhaps when our eyes are presented with an image that is ambiguous it is forced to come up with an interpretation that is the most likely under the circumstances. But our vision is governed by consistent principles. And this is the nature of visual intelligence, to construct, and to construct by means of elegant principles.
Without exception, everything you see you formulate with your visual intelligence - motion, shape, position, color, shading, texture, identity - and out of those elements you create the entire visual scene and its meaning. In 1851 the German physicist and physiologist Herman von Helmholtz revolutionalized the field of ophthalmology with his version of the ophthalmoscope. (Unbeknownst to Helmholzt, Charles Babbage invented the first ophthalmoscope 4 years earlier and gave it to a physician for testing, but it was soon misplaced and forgotten. Modern ophthalmoscopes are used during every eye examination by optometrists and ophthalmologists and are used to examine the retina and structures at the back of the eye.) But Helmholtz's endeavors were increasingly focused (pun intended) on the physiology of the senses and culminated in theories on color vision, depth perception and motion perception.
Helmholtz wrote, "The psychic activities that lead us to infer that there in front of us at a certain place there is a certain object of a certain character, are generally not conscious activities, but unconscious ones. In their result they are equivalent to a conclusion,... it may be permissible to speak of the psychic acts of ordinary perception as unconscious conclusions, thereby making a distinction of some sort between them and the common so-called conscious conclusions."
An eye-opening fact about vision is that children are skilled at vision before they are even able to walk. Before their first birthday they see a three dimensional world and can navigate through it quite adeptly, can recognize objects and grasp them skillfully with their hands. They are not taught how to see. Their parents do not sit down with them, after they have breast-fed or had their bottle, and explain to them how to determine shape, size, color and movement and how to use their two eyes together to judge depth. Indeed, the parents do not know how they do so themselves. And yet, every normal child, without being taught, creates a visual world similar to every other child - and solves the fundamental challenge of vision. The fundamental challenge of vision is that the image formed in the eye is subject to countless possible interpretations.
The fact that this is possible is because the principles of vision are a genetically determined part of the cognitive structure of the child. So children universally learn complex vision rules not because they are smart, not because they are taught, not because they are useful to them, but because they can't help it. It is their nature.
But occasionally there are roadblocks that interfere with normal vision development. Just as speech sometimes develops abnormally and requires the expertise of a speech-language therapist some children have a delayed or abnormal development of their vision skills which can interfere with their ability to do well in school or to excel in sports.
Specialists in vision therapy for children with delayed or abnormal development of visual skills are called developmental (or behavioral) optometrists. They are concerned with how well the child's vision functions. They are also specialists in the field of lazy, crossed or wandering eyes.
Five vision skills that can be improved by visual therapy are:
- Binocularity - the ability to use the two eyes together efficiently and comfortably. It is essential for normal stereopsis (3-D vision)
- Oculomotility- smooth and efficient eye tracking, essential for hand-eye coordination and skill at sports. ("Keep your eyes on the ball")
- Accommodation/Convergence - the ability to refocus your eyes from far-to-near and near-to-far. It is critical for efficient reading.
- Vision Perception - the skills needed to understand the world that you are "seeing" as described in the text above.
- Visual-Motor integration - vision is integral to our movement. Without good vision, movement is impeded. Without good movement, vision is impeded. The two are conjoined.
Some symptoms that are the result of poor visual skills:
- Headaches while reading or writing
- Words run together or blur when reading
- Loses place when reading
- Reads below grade level
- Head tilts or closes eye when reading
- Difficulty understanding what is read
- Hard to write in a straight line
- Holds book very close
- Burning, itching, watery eyes
- Doesn't finish tasks on time
Click here for a link to vision illusions