Understanding the Complexity of Cortical Blindness and Ch'en Ching-k'ai's Visual Impairment

Photo／Teacher Hsieh Man-li and appellant Ch'en Ching-k'ai

When special education teachers counsel and teach students with visual impairments, they must obtain a doctor's diagnostic report, such as the name of the disease, whether surgery was performed, and what kind of treatment was received (though certainly not limited to these). Importantly, we must know the age and cause of the illness. Taking Ch'en Ching-k'ai as an example, he suffered a visual impairment in his junior year of college while being an competitive athlete, which means his existing motor skills were very good. Furthermore, the cause of his visual impairment was a car accident resulting in brain injury, with a doctor diagnosing damage to the visual cortex while the eyeball structure remained undamaged. At this point, teachers must pay attention to whether he has an intellectual disability, physical disability, or other impairments. Next, teachers need to conduct a more complex understanding of the current visual status of a person with cortical visual impairment, namely how he sees and how he cannot see.

The textbooks used in the training of our visual impairment education teachers or visual impairment rehabilitation professionals teach this: 'Individuals with cortical visual impairment show a preferential response to objects of specific colors, with the most common color preferences being red or yellow, though any color may be specially favored. Individuals with cortical visual impairment are attracted to moving objects or objects with glowing or reflective surfaces (seemingly moving), to the extent that this attraction causes them to notice only moving things and ignore other stationary objects. When facing a complex visual environment with many targets around, individuals with cortical visual impairment find it difficult to classify or locate a certain symbol or object; this phenomenon occurs in both two-dimensional and three-dimensional situations.' There are seven other visual and behavioral characteristics of individuals with cortical visual impairment which will be omitted here. The purpose of our teachers evaluating these ten behavioral characteristics is to understand whether he is using his vision, or using other sensory strategies to cope—such as hearing, touch, etc., making a total of eleven sensory perceptions.

When our teachers know that a doctor has diagnosed a visually impaired student with a visual acuity value below 0.02, we know this is a person with severe visual impairment. Teachers have a lot of experience seeing visually impaired students with visual acuity values below 0.02 holding their eyes close to read words, with their ability to distinguish words falling between seeing and seeing clearly, meaning it is still blurry. Especially for adults who became visually impaired later in life, they can use past memories of word shapes and character features, as well as recognizing characters with fewer strokes, to deduce what characters might precede and follow. The above is a common reading strategy used by many visually impaired people. As for how close the distance is, some hold their eyes ten centimeters from the paper, while others hold them four or five centimeters away, varying from person to person. Of course, the distance is also related to the size of the characters presented on the paper, coupled with the problem of slow focusing, blurry vision, and a very small peripheral field of view (tunnel vision). This is like looking at a large character—magnified to a size much larger than a straw's diameter—through a straw; at this point, seeing the entire character clearly cannot be done quickly.

Next, let's talk about the impact of light on seeing. The vast majority of visually impaired individuals—if in conditions of insufficient light, a deficit that might make no difference to us—will find it makes a huge difference to them, potentially causing them to not see at all. However, the degree of brightness needed to improve vision varies from person to person. Sometimes the degree of brightness cannot be controlled; for example, in a three-bedroom, two-living-room house, the brightness of each room and each area is inconsistent. Living alone without needing to consider other family members might allow for slight control, or control might only be possible by adjusting the angle and brightness of a desk lamp on an individual's personal desk. Outdoor light and the angles of objects and the body interact with each other, involving backlighting, glare, reflection, refraction, and so on, making it even more complex and requiring more observation under which interactive conditions things can be seen.

Writing is also possible under blurry conditions. Our teachers will also test other visually impaired individuals who have similarly received diagnostic certificates from doctors for visual acuity values below 0.02, trying to see how they manage to write. If he was someone who frequently needed to write before his visual impairment, it means that the structure of characters is already stored in his brain. By utilizing blurry vision at close range, coupled with appropriate lighting for him, memory of character structures, spatial memory of the stroke movement required for characters of frequently written sizes, and of course diligent practice, it is possible to write characters very well. In other words, how severely visually impaired people read and write involves considering many conditions, not just reference visual acuity values. Admittedly, reading and writing at such close distances requires more time to complete than for ordinary people in terms of efficiency or speed.

Ch'en Ching-k'ai's eyes currently show no closing or blinking when exposed to strong light shined directly close to his eyeballs for more than ten seconds, under a distance and strong light that ordinary people could not endure. This is a tragedy; we can no longer understand his visual status at that time. Fortunately, some videos filmed at the time remain. We should have more experts who understand the visually impaired view these videos, which might help judges clarify some doubts.

Special education teachers for the visually impaired or related rehabilitation professionals are dedicated to teaching the visually impaired to be as independent as possible and to adapt to society—for example, learning how to maintain an upright posture when walking just like ordinary people, so as not to tilt the body due to using only one eye, ultimately leading to scoliosis. In other words, sighted people must be willing to understand our subjective impressions of the visually impaired, as attorney Li Ping-hung said; these all happen for a reason. I hope that successfully rehabilitated visually impaired individuals will not be suspected of being fake. We sighted people should calmly consider whether we are spinning in our own prejudices and blinding ourselves.

Teacher Hsieh Man-li 2018/3/16

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