Defining Boundaries of Low Vision Patients


Treatment and services for visually impaired veterans who are not considered legally blind.


Many visually impaired veterans who are not considered legally blind are at significant risk in their daily lives due to inability to see clearly with conventional correction. These veterans can benefit from early intervention and counseling, thus reducing the risk and safety factors. Currently, the VA does not have an organized, nationwide procedure for addressing the needs of visually impaired veterans.


It is strongly believed that early intervention with visually impaired veterans is crucial to the prevention of blindness, adjustment to vision loss and will reduce the risk and safety factors that occur with vision loss.

  1. Veterans identified as having a significant visual problem, (i.e. can’t read medication bottle label) should be referred to the VA eye clinic for examination as a priority.
  1. If the eye clinic is unable to restore the veteran’s vision to a normal level with conventional correction then the visually impaired veteran should be evaluated by a low vision specialist, either in the VA or local community, if not available in the local VA.
  1. Visually impaired veterans should be referred to the local Visual Impairment Services Team (VIST) program for review of benefits and services. VIST should refer visually impaired veterans to appropriate resources (i.e. diabetes education, talking books, etc.).
  1. The VIST program should continue to track those visually impaired veterans who have a prognosis for further vision loss at some point in the future. These veterans should be added to the VIST Roster as “non- legally blind” for tracking purposes only.
  1. The VA should establish at least one or more comprehensive low vision centers in each VISN.
  1. Veterans identified as severely visually impaired and potentially legally blind should be classified as Catastrophically Disabled. Many of these veterans face life threatening risk and safety factors but are denied access to VA care if their income exceeds the Means thresholds.

Issue Overview:

Since the late 1940s the VA has provided comprehensive rehabilitation services to legally blinded veterans. The VA is a recognized leader in blind rehabilitation and has played a key role in the modern development of the profession of blind rehabilitation. The BVA has been a strong advocate for the VA blind rehabilitation programs and has encouraged expansion of these services to meet the growing needs of blinded veterans.

However, there is a segment of the visually impaired veteran population that is at significant risk that is not served by the VA blind rehabilitation programs. This group of veterans are severely visually impaired, but not considered legally blind. Unfortunately, the VA lacks a comprehensive approach to provide appropriate services to this segment of the visually impaired veteran population.

The BVA is very concerned about this population of visually impaired veterans because the majority of blinded veterans began as visually impaired and could have used a comprehensive approach to vision loss prior to becoming legally blind.

Background:  Modern History of Legal Blindness

American society responds to the term legal blindness.  What does this term mean in the simplest form?  Is it the point where a patient can no longer read a medication label or read the newspaper, bills, appointment letters, syringes, glucometers, etc.?   No, the ability to read all of this is lost long before a patient reaches the threshold of legal blindness.

If this is the case then why is legal blindness such a crucial parameter?

The term legal blindness as used in America is a product of the 1930s. In 1934 the Federal Government asked the AMA to formulate a definition of blindness that could be used to determine which people were in need of special care due to their visual impairment.  The AMA wording was later incorporated into the Social Security Act as the definition of disability and basis for financial benefits. The definition also has to do with the insurance industry and the need to quantify vision loss in an effort to determine claims.  It is a normative reference.  An individual’s visual acuity is measured against the performance of a group of “normal” individuals.  The vision of these individuals was used to develop the eye chart.  A person may be determined legally blind by virtue of reduced fields of vision as well.  Visual field loss in both eyes below the 20 degrees range denotes legal blindness regardless of remaining acuity. The label of legal blindness is an arbitrary clinical standard that was developed over 60 years ago when there was little information about how people use vision for performing various tasks.

Legal blindness is an artificial barrier set up for a specific reason.  It provides a universal way to measure vision loss that has the same meaning in Maine, Florida, California, Alaska, and all points in between.

Legal blindness is a very understandable term that conveys a concept that is easy to transfer from location to location, professional to professional.  However, legal blindness in and of itself has limited functional meaning except for the fact that someone has a severe visual deficit. When one tries to put functional connotations on legal blindness the results may be less than clear.  An example will help to illustrate:

Can an individual who is legally blind read?

The questions generated by this are numerous.  Do they get to use optical aids?  How large are the target letters? Is there enough ambient lighting?  Did the individual posses the skill of reading before the sight loss?  The definition of legal blindness does not answer these questions.

Even worse, when one leaves the realm of legal blindness for the area of low vision (vision between normal vision and legal blindness) one gets mired in even more vexing questions.  It is clear that patients with low vision who cannot be “fixed” with ordinary glasses need intervention. This leads to some very basic inquires:

  • When does a patient become classified as Low Vision?
  • When is it appropriate to have intervention for these patients?

What type of intervention is needed?

The second question is the easiest to address, as soon as possible after the patient has been determined to meet the clinical indicators that reveal he or she is at risk without intervention

The other two questions pose more thought provoking responses.  To further define these questions one will need to look at the types of vision loss.  This document will attempt to quantify vision loss in a functional manner.  Then it will look at the possible types of intervention.

Quantifying Vision Loss

Legal Blindness:

Legal blindness = vision in better eye with best correction no better than 20/200 (as measured on a Snellen chart)

Legal blindness = visual field no greater than 20 degrees in both eyes.


Acuity is the clearest measure of vision.  It involves an eye chart, paper or projected and the response of a patient as compared to a normative group.  The term 20/20 refers to the individual seeing at 20 feet what that group saw at 20 feet.  The term 20/200 refers to seeing at 20 feet what that group saw at 200 feet.

Acuity is easy to understand and provides us with cold hard numbers.  But, it does not touch the need for functional information.  If the patient has 20/20 acuity, but a five-degree central field (OU) of view they would qualify for legal blindness based on field loss.  The same patient might be able to read road signs and the want ads during the day, and then be virtually unable to travel independently at night or in dim lighted environments.

If the patient had suffered multiple retinal detachments and the vision was restored with some measure of success, contrast sensitivity might be so poor that the patient could not function well in a dimly lit room.

Acuity provides a neat, clean threshold.  It cannot accurately describe functional ability when considered alone.

Field of View

The field of view alone can be the determining factor in sight loss.  Field loss when combined with other conditions can be devastating whether considered legally blind or not.  The most common example would be in homonymous hemianopia that coincides with a stroke.  The patient not only has a field deficit, but often also has neglect (the total ignoring of the lost area of view) which may further complicate the ability to function.

Contrast Sensitivity (CS)

Contrast sensitivity was alluded to in an earlier example.  Acuity test charts tend to be stark, pure black on pure white.  The world is a world of shades of gray.  Degraded CS impedes the ability to see that world.  Plus, CS may impede the ability to use optical aids effectively and call for the need of improved lighting and electronic magnification. The entire concept of luminance revolves around lighting. Aging is related to the need for increased lighting.  It is estimated that the same patient with 20/20 vision requires twice as much lumination to read at age 65 as compared to age 20.

Diplopia and other Conditions of Binocularity

Diplopia is not always as simple as double vision and patching one eye.  If one looks at the VA rating scales for vision, an individual may be 100% service connected based on Diplopia.  The loss of binocularity is an impediment not only in the area of vision but also in depth perception.


Scotoma refers to lost portions of vision in an entire field.  In some cases acuity can remain the same but a macular scotoma can interfere with sacaadic movements of the eye.  In such a case relatively small portions of vision loss may be devastating to the ability to read smoothly.

Color Vision

When color vision is mentioned the inability to tell wires apart comes to mind.  Color vision loss presents problems in the everyday world.  Modern streetlights were developed with a red, yellow, and green pattern expressly to deal with Red – Green color blindness.  It represented environmental modification 70 years before ADA.

Glare, Light – Dark Sensitivity and other considerations

All of these factors can present functional problems.  Each variable considered individually could be no more than a hindrance.  However, when combined with other eye disorders and with the right type of activities minor hindrances may become major barriers.

Eye Diagnosis

Eye diagnosis alone does not translate into acuity, but it may give indications of severe deficit.  An example of this is Retinitis Pigmentosa.  A person with RP may function very well in the daylight hours and in fact they could easily test at 20/20.  However, at night under low lighting, the same person might have severe functional problems.

Additional Notes on Vision Loss

Vision loss is now being recognized as a contributing factor in falls among the elderly.  Fall related injury is a major cost and concern in the field of health care. Fall risk does not begin at the point of “legal blindness”.

It seems clear that patients do not first begin to experience real life problems when the vision reaches the point of legal blindness. One has to look at the patient’s ability to function in real life activities of daily living.  There are many conditions that lead to impaired visual functioning.

Simple need for regular eyeglasses can cause problems with visual functioning. A patient with uncorrected vision can present with profound impairment. Severe myopia without correction can leave a patient as impaired as someone legally blind.  Fortunately this type patient is covered for glasses in the VA. The medical doctor simply needs to document that the patient cannot “participate in medical treatment” without the provision of eyeglasses.  Without their corrective lenses, many individuals would be functionally “legally blind”.

Non-legally blind patients may have operable or pre-operable cataracts that impede visual functioning to the point where intervention is indicated. There may be an extended wait for corrective surgery. The surgery may be delayed due to ongoing medical issues that interfere with medical clearance to have the cataract surgery. The patient thus may face an extended period of poor visual functioning. During that wait he or she still has to manage medications and read mail and so forth.  This type patient is not “legally blind” but certainly could have severe, even profound functional vision impairment until undergoing corrective surgery.

Patients with diabetes pose complicated management issues. Many of these patients are not “legally blind” but face continuing problems with visual efficiency.  Visual functioning can vary during the day. Elevated blood sugars can cause problems with visual functioning that can severely interfere with such activities as reading insulin syringes and blood glucose monitors.  If these individuals do not receive timely intervention it could be a life or death situation. Many diabetics reach the point of being considered low vision and may remain in a pre legal blindness state for an extended time. Due to the risk for medical complications, these individuals must have intervention.

Defining Functional Vision Loss
A patient with low vision is a person who has difficulty accomplishing visual tasks, even with prescribed corrective lenses, but who can enhance his/her ability to accomplish these tasks with the use of compensatory visual strategies, low vision and other devices, and environmental modifications.

The World Health Organization (WHO) defines various ranges of vision loss instead of the standard definition of “legal blindness” The definitions used by the WHO is also the basis for the official classification used in the United States issued by the  National Center for Health Statistics. In ICD-9 –CM the level of vision loss previously identified as “legal blindness” is changed to “severe vision loss”. This is more than just a change of words as it signifies a change in attitudes. The term “legally blind” is based on a dichotomous view vision loss and thus supports the concept of a dichotomy in service delivery. The term “severe vision loss” is based on a continuous scale of ranges of vision loss and thus promises a continuum of service delivery and smoothly integrated teamwork.

Two definitions of functional vision loss are worth special attention.

First Source:

Functional visual impairment is a significant limitation of visual capability resulting from disease, trauma or congenital condition that cannot be fully ameliorated by standard refractive correction, medication or surgery, and is manifested by one or more of the following:

1) Insufficient visual resolution (worse than 20/60 in the better eye with best correction of ametropia)

2) Inadequate field of vision (worse than 20 degree in the widest meridian in the ey with the more intact central field; or a homonymous hemianopia)

3) Reduced peak contrast sensitivity (<1.7 log CS binocularly)  AND

4) Insufficient visual resolution or peak contrast sensitivity (see1 and 3) at high or low luminances within a rang typically encountered in everyday life

Source:  Arditi & Rosental. Developing and Objective Definition of Visual Impairment.  New York:  Arlene R. Gordon Research Institute, The Lighthouse Inc., 1996.

Second Source

The term “vision impairment” means vision loss that constitutes a significant limitation of visual capability resulting from disease, trauma, or a congenital or degenerative condition that cannot be corrected by conventional means, including refractive correction, medication, or surgery, and that is manifested by one or more of the following:

(A) Best corrected visual acuity of less than 20/60, or significant central field defect.

(B) Significant peripheral field defect including homonymous or heteronymous bilateral visual field defect or generalized contraction or constriction of field.

(C) Reduced peak contrast sensitivity in conjunction with a condition described in subparagraph (A) or (B).

(D) Such other diagnoses, indications, or other manifestations as the Secretary may determine to be appropriate.’

Source:  H.R. 1902, presented in May 2003 to the first session of the 108th Congress.

Comments on Low Vision Definitions

A review of the literature reveals there probably is no one perfect definition of low vision that covers the range that is sandwiched between normal vision and legal blindness. Visual impairment is not a black and white issue. Every patient, even those with the same diagnosis and acuity rating will functionally see differently.  Two patients with 20/100 visual acuities do not respond to exactly the same interventions. Each must have an individualized low vision assessment to determine what specific optical devices to prescribe.

The two operational definitions given above have some striking similarities.  They both:

  • Start at 20/60
  • Recognize field restrictions
  • Recognize contrast sensitivity degradation in conjunction with other eye impairments
  • Leave room for review on a case by case basis

The last item, “Leave room for review on a case by case basis,” is no doubt the most important and should drive all clinical intervention no matter where the patient’s functional vision lies along the continuum.

In light of possible reimbursement for low vision services in the near future, it is recommend that strong considerations be given to an operational definition of low vision that mirrors the one given in H.R. 1902 (20/60).  It seems to meet with other definitions in the field and it would provide a sound base for business considerations in the future. The VA will want to position itself to collect reimbursement in the future.

What constitutes Appropriate Intervention

The intervention needs to match the need. The patient who cannot read medication bottle labels due to the need for regular eyeglasses needs to be provided eyeglasses.  If the diabetic requires a lighted magnifier-lamp to properly draw insulin into a syringe then the device needs to be issued whether the patient is legally blind or not.

The vast majority of low vision patients who will be referred for intervention (services) will require the provision of the correct optical devices.  Many if not most will benefit from lighting improvements.  In most cases these two interventions will restore function and reduce the risk.  A comprehensive low vision exam and the provision of the prescribed optical devices can be expected to be the core interventions. However, the eye care professional may prescribe a wide array of low vision aids based on vision loss, functional goals, and considerations such as the patient’s physical ability and preferences. The intervention has three parts:

  • Low vision exam
  • Provision of optical devices
  • Timely process for the above two

Beyond the provision of optical devices by the eye care professional, VIST or BROS might be called upon to issue things such as large print watches, address books, etc.  Home modifications might be appropriate.  These will vary from case to case.  It is very possible that a patient with a case of dry age related macular degeneration would need no more than low vision aids when they are in the “20/60” vision range.

Other Interventions

It is possible that anywhere along the spectrum of sight loss from 20/60 to 20/200 an individual will need some intervention beyond optical aids.  This will have to be judged on a “case by case” basis based on the clinical indicators.  Recommendations of the eye care professional will help trigger the need for other intervention.

The diabetic patient may require referral to diabetic teaching for assessment of the proper blood glucose monitor that is accessible.

All low vision patients will benefit from being provided educational materials and information about community services that are appropriate. An attempt needs to be made to not only restore lost function but to prevent further complications such as additional sight loss, depression, isolation and so forth.  Specific interventions for a particular patient will depend on the clinical indicators present.

Continuum of Care

The following is a look at how a continuum of services might be provided in regards to vision loss.

Acuity Explanation Education on Eye Disorder Low Vision Aids Other Services
20/20 – 20/60 Start of Eye Disease or Disorders, relatively early stages.Ambler Grid-ARMD Material on specific eye conditionInformation on: LightingFalls Simple Glasses,Simple devices to assist in reading or medications management if needed. Low Vision Exam * Based on functional abilityDiabetes Education
20/60 – 20/200 Progression of eye disease.  Functional loss and loss of driving evident. Material on specific eye conditionInformation on: LightingFallsCommunity Services




Ambler Grid use-ARMD

GlassesLow Vision AidsNon-optical aids as neededElectronic aids case by case Low Vision ExamVIST ServicesVICTORSVISOR

Community Services


ADA Travel  (if allowable)




Diabetes Ed.

20/200 – Total Blindness Severe impairment ranging to total loss of vision.Total loss of independence possible Material on specific eye conditionInformation on: LightingFallsCommunity Services


Family training


Ambler Grid use-ARMD

GlassesLow Vision AidsElectronic AidsNon-optical aids as needed Low Vision ExamVIST ServicesBRCVISOR

Community Services


National Services


ADA Travel


Diabetes Ed.



There is a need to provide intervention to patients with severe visual impairment but who are not classified as legally blind.  It is impossible to determine what specific intervention a patient will require at a specific level of vision. There are too many intervening variables as discussed above. The determination of what services are required depends on the clinical assessment-the clinical indicators. The one thing that all such patients present with is problems in functioning.

It would seem that the functional problems that will require the most immediate intervention regardless of level of acuity are related to risk management.  If a patient is a diabetic and cannot read to correctly load the syringe, this would be a clear clinical indicator for intervention.  If a patient cannot see well enough to correctly read medication bottle labels this would be a clinical indication for intervention.

If a patient were experiencing a mobility problem that could result in injury this would be considered a clinical indicator for the need to intervene. This would include problems with running into objects and fall risk.

Generally, patients with a level of visual impairment indicating that their heath could be adversely effected will be identified as having a need for intervention by their health care professionals and/or eye care professionals. For example the patient could be seen in an eye clinic where the examination determines that nothing medically or surgically can be done to restore functional vision without the use of low vision devices. That would constitute a clinical indicator to refer the patient for a low vision assessment.

Almost always a patient referred for low vision services will complain of significant problems with the following:

  • Cannot drive anymore and thus has problems accessing medical care, shopping
  • Cannot manage financial affairs-manage the check book, read financial statements
  • Cannot read mail including medical appointment letters, bills
  • Cannot read the newspaper
  • Cannot see TV well enough to enjoy it
  • Cannot read medication bottle labels
  • Cannot see peoples faces
  • If a diabetic, cannot draw insulin, cannot read blood glucose monitor and cannot see to

Safely cut toenails

  • Problems reading labels while shopping
  • Problems with travel in dim light
  • Lack of education about available services
  • Has no eyeglasses
  • Cannot read city bus numbers anymore
  • Cannot see their computer monitor anymore
  • Awaiting cataract surgery
  • Severe problems with glare
  • Severe problems with depth perception
  • Severe problems with contrast sensitivity
  • Problems driving at night
  • May lost employment
  • Problems functioning in school
  • Problems with currency identification

If a patient is not experiencing the type problems listed above there is usually no clinical indicator for a referral and intervention.

The major focus of intervention with low vision patients is to reduce risk of injury. It is expected that earlier intervention will lead to better long-term outcomes.

Expected outcomes:

  • Improved medical management
  • Improved compliance
  • Restore effective functioning
  • Maintain employment
  • Restore employment
  • Remain in school or return to school
  • Prevent or slow progression of impairment
  • Increased independence
  • Prevent falls
  • Prevent –better manage frustration, anxiety, depression, regression, and isolation
  • A more educated patient
  • Increased quality of life
  • Reduce medical complications
  • Prevent or delay nursing home placement

The role of Visual Impairment Services Team:

The benefits of using the VIST program as a partner during the intervention with the non-legally blind low vision patients should be evident The VIST is already established and is the recognized local subject matter experts in most facilities for matters related to patients with low vision. The issues faced by patients who are legally blind are essentially the same functional issues faced by the patient with severe visual impairment. Adding the responsibility of providing intervention to patients when the clinical indicators indicate risk seems to be a natural extension in a continuum of care and services model.  Using the clinical indicators of risk will ensure the referrals are proper and manageable. Many good VIST programs are already providing such services as the “Right thing to do”.

In the VA there are already policies and guidelines supporting the provision of services to all “enrolled” visually impaired patients.  If a veteran is enrolled and cannot participate in his/her medical care due to vision or hearing impairments then that veteran can be provided restorative services including hearing aids and eyeglasses. The same rules that provide eye glasses to veterans who cannot participate in their medical care (cannot read medication bottle label) would apply to a low vision patient needing low vision optical devices to read medication bottle labels. It would seem to be illogical to not provide these services.

Early identification and intervention should reduce the cases of clinical depression.  Early intervention will restore functional ability in a timely manner.  Positive by-products of interventions should include reduction of falls and better patient participation in health care. Intervention for the low vision patient will also set the stage for the treatment pathway as sight loss continue into the realm of legal blindness.

The benefits to the VA are twofold. First, we are probably looking at a future pathway to reimbursement in an expanded Medicare driven low vision services market.  Second, patients who are able to effectively see will be more accurate in medications, reading appointments, and carrying out activities of daily living that are beneficial to health maintenance, reduction of negative outcomes, and containment of health care expenditures.

The VA would do well to establish a simple benchmark for low vision services:

Patients should be continuous able to read throughout the progression of their sight loss.  This is not a “high minded’ concept, it is a very basic one.  Individuals in our society who cannot read are at risk.  Inability to read may mean the inability to take medications accurately, read mail, show up at critical appointments, pay bills, shop for food, etc.

Not providing reasonable interventions to patients with functional visual impairments would be akin to when we have a ”legally blind” veteran who has waited for months to enter a residential blind rehabilitation center and during the wait has remained at risk unable to read because of the lack of intervention and provision of the appropriate low vision optical devices. We should view each of these cases as a failure of the VA system to provide critically needed care to the patients.