Reassessing the Applicability of Low Vision Services

Using a functional definition of low vision broadens the scope of patients who would benefit from services.

By Bradley Kehler, OD

Low vision services are applicable to more patients than many eye care specialists may realize. Although low vision is most commonly defined in terms of visual acuity—20/60 or worse in the better-seeing eye by Medicare and the World Health Organization, for example—there is a functional definition that applies much more broadly. In reality, many patients have deficiencies in their vision that disrupt their daily activities and thus may benefit from a referral.

Low vision services are vastly underutilized, which may be borne out of misunderstandings about the services offered by a low vision clinic. The popular perception may be that specialists provide devices to restore acuity or to help compensate for vision loss—for example, magnification devices for patients with central visual defects. Although this is true, many may be surprised to learn the extensive amount of educating and counseling of patients that goes on in low vision clinics, or that specialists often serve as a coordinator of care among a wide range of specially trained experts who help patients cope with their loss of visual function.

Low vision services are not simply a one-time fix; rather, they are part of a process of helping patients find solutions that enable them to live more fulfilling lives despite their loss of vision. In actuality, if a patient’s acuity loss is not attributable to routine refractive errors, and if there is known ocular pathology and functional impairment, then he or she likely would benefit from a referral to a low vision specialist.


The most common pathologies associated with a need for referral include age-related macular degeneration, glaucoma, field loss from stroke, and inherited retinal diseases like retinitis pigmentosa, Stargardt, and cone dystrophy. Generally speaking, there are two components to the services that are rendered by low vision specialists. The first part is recommending a solution for the particular problem, which follows from a complete assessment and testing of patients’ visual ability. The second part involves getting the patient adequate training to be able to take full advantage of his or her recommended therapy, whether that is the use of a device or a compensatory change in how he or she completes a vision-related task.

In the case of central vision loss, the goal of therapy is to increase the size of the perceptible target, which may entail optical or electronic (camera-based) magnifiers. Specifically, this could be using a closed-circuit television for reading mail, or an iPad (Apple, Inc.) or computer software for e-mail and online news. Many low vision specialists will demonstrate use of the product or device, but other specialists may also be involved in the training.

If a patient has peripheral field loss due to something like hemianopia, the use of prisms affixed to glasses may help him or her compensate for scotomas or field deficiencies. In the cases of advanced glaucoma, diabetic retinopathy, or hereditary fundus dystrophies, full orientation and mobility training may be needed, which requires a referral to an orientation and mobility specialist.


Low vision practitioners work closely with a team of specialists—either in a single clinical setting or in a network—that includes the referring ophthalmologist or optometrist, low vision therapists, vision rehabilitation therapists, orientation and mobility specialists, and occupational therapists. In this regard, the low vision specialist may function as a quarterback, coordinating the interaction of the patient with the whole team of specialists acting together to restore functional ability.

Occupational therapists and vision rehabilitation therapists are responsible for evaluating function as it pertains to visual impairments. That assessment may include such things as how well a patient can dress him- or herself or how well he or she can interact with family members, cook meals, shop, perform job functions, sort out medications, or participate in leisure and social activities. The therapist may then recommend a course of action to address any negative findings in the evaluation.

Certified low vision therapists will typically train patients to use the skills and technologies that are identified as potentially useful. They may train a patient on the proper use of an optical device, how to mark appliances to help with identification, or they may help patients discover new ways of doing daily activities, such as cooking and cleaning.

Orientation and mobility specialists teach patients to use their remaining senses to orient and navigate. The training may involve the use of a white cane, but these specialists also teach patients how to interact with the world without visual data. For example, they may teach patients how to safely cross a busy street, how to follow landmarks, and how to locate objects.


Any or all of a number of specialists may help manage patients in need of low vision services. The low vision optometrist often acts as coordinator, not necessarily performing all the rehabilitation components him- or herself, but ensuring that the patient receives the exact services required from multiple professionals. A patient working with a low vision clinic is analogous to a patient healing from a broken leg; after the surgical work is done, a team of experts helps that patient regain strength in the limb and regain mobility and function. In the same way, low vision optometrists collaborate with various other specialists to help patients achieve their visual goals while also ensuring the ongoing care of their underlying pathology.

Bradley Kehler, OD, is an assistant professor of ophthalmology at Vanderbilt Eye Institute and an assistant chief medical information officer at Vanderbilt University Medical Center. Dr. Kehler may be reached at (615) 936-5679;

Suggested Reading

More information about the various specialists who work with low vision patients can be found at the website for the Academy for Certification of Vision Rehabilitation & Education Professionals at

More information about ongoing research in low vision services can be found at the website of the Lions Vision Research and Rehabilitation Center of the Wilmer Eye Institute of Johns Hopkins University School of Medicine at This organization also supports an online peer-to-peer network for low vision professionals called the Principles & Practice of Low Vision Rehabilitation, which can be found at