The Global View

Funding is generally not available in the developing world for blind rehabilitation. Furthermore, support for high technology is deep down on the priority scale. This lack of attention to rehabilitation is the result of an understanding of the global demographics of blindness. Internationally, we are faced with medically preventable impairments, needless blindness, in the third world. There are over 50 million blind individuals in the world according to the World Health Organization. Conservatively, 40 million of these people should not be blind and could have their blindness reversed anytime they received medical attention. Given these demographics it makes no sense to spend money on sophisticated blindness technologies for people who could have their sight restored with a fifteen minute cataract operation, or a dose of antibiotics, or sufficient nutrition (Vitamin A), or a few simple surgical procedures. Needless blindness is a worldwide pandemic caused by injustive and poverty. The world's first priority is medical intervention, not rehabilitation.

Depending on the cause, up to 80% of blindness and serious vision loss can be prevented or treated. The major causes of avoidable vision loss are: cataract, trachoma, and glaucoma; they account for 70% of the world's blindness. Cataract accounts for an estimated 16 million cases of blindness worldwide; it accounts for approximately 1/2 of all cases in most countries of Africa and Asia. Trachoma, the 2nd leading cause of blindness worldwide is the cause of 15% of all blindness. There are about 6 million persons with irreversible blindness due to trachoma and 146 million with active cases in need of treatment. Glaucoma is the 3rd leading cause of blindness worldwide and is responsible for about 5.2 million cases of blindness. Estimates of the number of persons worldwide who have glaucoma range from 67 million to about 105 million cases. River blindness" (Onchocerciasis) accounts for about 270,000 cases of blindness worldwide - almost 99% of these cases are in Africa.

Diabetic retinopathy is the leading cause of blindness and visual impairment in economically developed societies. Macular degeneration is the most common non-avoidable cause of vision impairment. It is estimated that about 8 million persons worldwide are blind or severely visually impaired due to macular degeneration.

Demographic Challenges in the Modern World

The normal blind traveler is defined here as an individual about 25 years of age who is in good health and has no secondary cognitive, physical, or other sensory damage to the body. Using these criteria, we find that there are very few "normal" blind individuals in the world.

Blindness usually occurs because of serious damage to the eye or to the brain. There is almost always secondary damage of some degree. In the industrial world, most people who are blind or severely visually impaired (legally blind) are older adults experiencing the ravages of aging- sensory lost in hearing and touch is combined with vision loss, physical aliments are typical, and some degree of cognitive processing degradation often accompanies aging.

A second large category of blind individuals are multiply impaired; they were born with genetic or birth anomalies that cause not only blindness but unique varieties of secondary impairments. Many of these individuals are mentally impaired.

Eye and brain damage also occurs in individuals who have been in serious accidents. A wide variety of unique multiple impairments affects this population.

The only categories of blindness where there are normal blind travelers occur with genetic disorders like retinitis pigmentosa- these blind people can become (often are) exceptionally good travelers. There is also a category of blind individuals who have injuries from accidents that selectively affect vision, but where secondary involvement is absent or has minimal impact on daily living.

Developmental Demographics

The ever changing nature of individual circumstances continually alters the technological choices that impact the blind consumer. The school years for the blind child unfold developmentally, so that every new year presents parents, teachers, and technology specialists with essentially a "new child"; one that has a whole different set of capabilities and challenges from "last years child".

The degradation of aging that impacts seniors progresses further with each passing year; different technologies and strategies must be applied over time.

Improvements in surgical techniques, drug therapies, and in the use of new technologies- especially chip implants and genetic or tissue engineering- result in consumers with new varieties and degrees of vision impairment (some never seen before).

All of these evolutionary events dictate that technology must be custom designed for individuals or for very narrow demographic populations. Furthermore, our solutions should never become static- the flow of technological application must match the flow of human change.

Alongside this is the ever progressing nature of the technologies. The bottom line is that upgrading technology and training in the use of technology are life long events for the blind consumer, as well as for their teachers, family, and for the technology specialists who serve them.

The Complex Demographics of Visual Disability

Most people who have damage to their eyes or vision system are not totally blind. Given the incredible sophistication of the vision system, the different types and degrees of vision that result from organ or brain damage, are considerable. One could make the case that every person with a vision impairment has a unique sensory system. Individuals with severe degrees of damage to their vision often receive the label "legally blind". This is a general legislative designation that gives the unfortunate impression that the legally blind demographic is homogeneous, rather than extremely diverse.

The Extreme Perspective

Human beings are basically blind creatures, both temporally and spatially. Vision is a head-mounted, straight ahead sensory system. It is spatially blind above, below and in the rear. As the head swings around to attend in a given direction, it becomes simultaneously blind in all other fields. Vision is also temporally blind, lossing contact with the brains processing system between the moments of attention. Furthermore, when concentrating, the brain suppresses input from non-essential fields; when listening entently to music, for example, the vision system is dampened or suppressed. The vision system may be a very powerful parallel computer, but attention is serial and it requires inhibition. In our multitasking, information overloaded modern world, there are many blind moments.

As human beings move the features of handheld computer/phones onto head-mounted units, we will begin to see digital vision systems emerging. These systems will enable ultraviolet seeing, infrared vision, 360 viewing, digital enhancement of near objects and telescopic digital enhancement of far objects. What will the definition of blindness become when some cyborgs see in such depth and with such variety of perceptual modes?

Inattentional and situational blindness fit the demographics discussion here

There are demographic rainbows. From the very young to the very old, there are developments and degradations of the perceptual system. Between total blindness and complete vision there are degrees of visual system "dysfunction". There is a bell curve ranging from those with very little demand on their visual system, few life tasks that require high perception, to those individuals with extreme visual task demands. There is a poverty sine wave that defines those with needless, curable blindness to those with no current medical solutions to their impairments, a curve that closely matches the economic status of individuals and their cultures. There is a rainbow of individuals that spreads from severely multiply impaired blind people, to those few with blindness and no other physical problems.

Notes:

The above WHO statistics are rusty.