Chances are that you have a friend or relative with permanent, uncorrectable, vision loss or, perhaps, have some loss yourself.  Despite this, unless you are directly involved in the lives of vision impaired people you have little understanding of the impact vision loss has on one’s life, the causes of vision loss, the legal requirements for blindness, or sources of aid for the blind and visually impaired. Many people hesitate to ask questions of individuals with disabilities about their disability.  Most visually impaired or blind individuals are happy to help educate you about their impairment.

This is meant to be a primer on visual disability and blindness, not a complete treatise.  In the six years since I have experienced sight loss I have been asked some questions often.  Other questions that might be, are never asked.

Frequently asked questions:

“What can you see?”

This is a straightforward question, but the answer is not.  We don’t really have words to describe abnormal vision.  Individuals with the same vision loss process describe their vision differently.  Attempts to use some illustration of what seeing people experience are largely unsuccessful.  I describe my own vision as one of almost complete loss of peripheral vision with central vision that varies from pinholes of residual altered vision ranging from blurry, to looking through ground glass, to a vague perception of movement.  Added to this are continual flashes of light similar to what you see when you rub your eyes.  But, none of that is really like what I see.  It’s is just an attempt to give some impression.

“Since you have lost your sight have all your other sense become more acute?”

No.  There is no magical increase in the sensitivity of other senses.  However, individuals with sight loss learn to pay attention to their other senses in ways sighted people don’t find necessary.  Individuals with hearing loss often aren’t aware that they have begun reading lips until they experience vision loss.

“Why are you using the (white) cane?  I thought you could see a little.”

Canes are used in different ways depending on the individual’s needs.  People who are completely blind find boundaries, landmarks, and establish the nature of the surface they are walking on.  Some people with some preserved central vision, but no peripheral vision “feel” the unevenness of the ground, avoid low obstacles, and let those approaching from the side know that they cannot see to the side.

“Do you have macular degeneration?”

This is a very common cause of vision loss in the elderly and a logical assumption.  However, there are many causes of vision loss and many older people have other eye disorders.  Other common causes are Diabetic Retinopathy, Glaucoma, and Retinitis pigmentosa.

“What caused you to lose your sight?”

In my own case the answer is very unsatisfying; unknown.  In the case of many blind or vision impaired people this is the answer.  “Unknown”, makes people uneasy because of the possibility that they might become disabled in the same unknown way.  There are often predisposing risk factors that play a part, but in most cases, folks with the same risk factors never experience a problem.  In the case of age related macular degeneration, a disorder which makes 200,000 Americans a year become legally blind, the risk factors include white race, light eye color, a diet lacking in green leafy vegetables and yellow vegetables, deficiency of omega-3 fatty acids in the diet, family history,  and exposure to sunlight without glasses that screen U.V. rays.  You can’t do anything about your family history, but you can wear sunglasses which filter UVA/UVB rays, improve your diet and get Omega-3 fatty acids from some dietary source like salmon or other cold water fish, or supplements that use vegetable sources for the fatty acids.

Glaucoma is totally silent and almost entirely preventable.  Annual eye pressure checks by either an Optometrist or Ophthalmologist can detect the increased eye pressure that leads to glaucoma.

Diabetes mellitus is a common source of vision loss and it is felt that good diabetic control can prevent this complication.

“If you have so much vision loss how do you get around so well?”

This is a good question.  While some people who ask this are suspicious, most are amazed and puzzled.  Folks with vision loss make mental maps of their surroundings and quickly learn to navigate familiar areas as though they can see.  This process works amazingly well, but just try moving something in the room and find out how susceptible blind people are to a change in their surroundings.  They will fall over things put in their pathway, and be unable to find familiar objects that have been moved even a short distance.  A friend of mine refers to this mental map as my internal GPS.

“How do you use a computer?”

There are several good software programs making computer use accessible.  For those with some residual vision, the software magnifies, reads pages and documents, changes colors, reverses field and ground, makes the mouse pointer more identifiable, and in other ways provides support.  An excellent program for those with low vision is Zoom Text, an AI squared product.  Those with complete vision loss commonly use JAWS.  This program requires a great deal of training because all commands are produced by key strokes and feedback is all produced audibly.  This program is cumbersome and some web sites are practically unusable, but the facility that blind people develop with this program is truly amazing.

“Did they fix your eyes at Blind Rehab?”

This is another logical question.  In physical rehabilitation the aim is to restore function.  In drug rehab the intent is to establish a drug free existence.  Blind rehab, on the other hand, is primarily intended to teach alternative ways of coping with life.  My own experience was through the Veteran’s Administration, but there are a number of good programs for non-veterans that cover the following areas:

Orientation/Mobility: The intent here is to develop ways to arrange your living quarters so that let you find things, learn to use the white cane, learn how to identify obstacles and landmarks, establish routes of frequent travel, find ways to cross intersections (and determine which intersections are simply not navigable) and find one’s way to a new destination.

Living Skills:  This addresses the activities of daily living such as cooking, doing laundry, ironing, cleaning, and personal grooming. 

Manual Skills:  In this phase the emphasis is on determining what the individual’s manual limitations may be, teach the use of feel to substitute for sight, and teach safety.

Visual Skills:  For the partially sighted this provides tools for using your vision in novel ways, finding tools that may improve your limited vision, and strengthening whatever vision may be left.

Computer Skills:  This is taught separately at the VA Blind Rehab Centers, but is an important tool for many.

Types of vision loss:

Eye diseases leading to blindness can be classified in a number of ways; fixed vs. progressive, central vs. peripheral, and inherited vs. acquired are examples. I have one of the less common forms of eye disease leading to vision loss; non-arteritic anterior ischemic optic neuropathy.  This is a form of non inherited, acquired, fixed, peripheral and central vision loss.  Other examples of peripheral vision loss are retinitis pigmentosa and glaucoma.  Retinitis pigmantosa is inherited and progressive.  Glaucoma is also progressive.  Retinitis pigmentosa has no present prevention or treatment.  Glaucoma is preventable through regular checks with the eye doctor and treatable, although damage already done cannot be reversed.  Both glaucoma and retinitis pigmentosa may end in complete inability to perceive light.

Macular degeneration is most commonly acquired and age related.  There are some inherited forms, however, that are not age related.  Both forms lead to central vision loss with preservation of much of the peripheral vision.  Some people with age related macular degeneration may be treated with medication regularly injected into the eye. 

Diabetic retinopathy tends to cause central vision loss and it is felt that good diabetic control may prevent this vision loss.

Legal issues and Definitions:

Blindness is defined legally as either 1) central vision loss resulting in visual acuity less than 20/200 in the better eye, or 2) an arc of vision that is 10 degrees or less in the better eye and 20 degrees or less in both eyes. To put this into better perspective, in the first case that is not being able to see at 20 feet what normal people can see at 200 feet.  In practical terms the individual can no longer make out the “Big E” on the Snellen chart in either eye.  The normal individual sees an arc with both eyes of about 220 degrees.  Legal blindness for the person with loss of peripheral vision requires an arc less than 10% of normal.

Anything better than these definitions, but not correctable to 20/20 in either eye is classed as visual impairment.

Individuals with disorders like retinitis pigmentosa and macular degeneration go through years classified as visually impaired before their vision becomes sufficiently bad to be classified legally as blind and eligible for various forms of aid.  In both cases individuals have lost the ability to drive, and generally have lost the ability to gain employment in the way they previously did.