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Professor Barry Kran’s Guest Blog

The role of optometry in the diagnosis and management of individuals with cerebral vision impairment (CVI).

Dictionary definitionDictionary definition

Optometry is a healthcare profession that is autonomous, educated and regulated (licensed/registered), and optometrists are the primary healthcare practitioners of the eye and visual system who provide comprehensive eye and vision care, which include refraction and dispensing, detection/diagnosis and management of disease in the eye, and the rehabilitation of conditions of the visual system.

The World Council of Optometry definition

The training and scope of practice of optometry varies from country to country (see references below for more information).

To meet the needs of the population worldwide, there is ongoing growth in the depth and breadth of both optometric training and practice (reference below).

In some areas of the world, such as the USA and Canada, becoming an optometrist requires an undergraduate degree followed by four-year Doctor of Optometry degree training at a College of Optometry. In other countries, it is part of an undergraduate program while in others, one can continue on to a master's degree.

The level of training of the optometrist and the individual's level of skill and interests will determine their potential ability to be actively involved in the diagnosis and management of children with cerebral visual impairment (CVI).

Generally speaking, most optometrists should be able to perform a primary care examination in children and determine the need for glasses for both optical errors and for lack of focusing (unless excluded by local law from seeing individuals below a certain age). Those optometrists with additional rehabilitative (low vision and/or vision therapy) and pediatric eye experience and training have a higher level of involvement in the diagnosis and management of individuals with CVI.

They are more likely to

  • have the training to collect data from this diverse population
  • perform clinical functional vision assessments
  • abstract pertinent information from the relevant medical, psychological, educational and occupational therapy reports.

This information enables the optometrist to make a diagnosis and to provide appropriate low vision services and recommendations regarding communication symbol size, initial considerations for print size, basic environmental adaptations, and positioning of the child in the learning areas for best access to the information. They should interface with those delivering services in the classroom, either though reports or preferably through conferences or local training so as to increase each other's effectiveness in caring for this population.

Ophthalmologists, optometrists and those in the community delivering services (such as vision educators) should coordinate their care and services for the betterment of the children in their local regions.

Optometry & CVI in USA & Canada

In the USA and Canada the optometrist is a member of an interdisciplinary team that serves a geographic area, assessing children with educational concerns. This team may include vision educators, psychologists, occupational therapists, and physical therapists. These teams diagnose, develop treatment plans and consult with the local team to ensure successful implementation of their recommendations.

Examples of different teams in the USA & Canada:

  • 1 Some eye care clinics see a range of children with vision impairment. Often these clinics receive referrals from a variety of sources such as vision educators, neuro-psychologists, and pediatric ophthalmologists requiring the optometrist to perform a functional clinical low vision evaluation, which could include the possible need for the diagnosis of CVI. Appropriate traditional low vision care, advocacy and recommendations are provided both face-to-face and in the report to the family and appropriate providers and educators. Patients are typically co-managed with ophthalmologists. In some cases, the optometrist is primarily involved with primary and low vision care with periodic referral to ophthalmology services and in other cases the optometrist is the member of the eye care team who concentrates on the functional low vision aspects of eye care.
  • 2 Many specialist pediatric eye care departments throughout the US incorporate pediatric optometrists to manage numerous patient types referring to the ophthalmologist as needed for consideration of surgery. These optometrists fit the required contact lenses after removal of congenital cataracts, perform assessment of vision with both eyes together, and in some cases perform vision therapy as well as providing some level of the care outlined in point one.
  • 3 There are pediatric and or developmental optometrists who focus their practices upon individuals with refraction and focusing issues, learning and vision issues, brain injury and the care of individuals with developmental and neuro-developmental disabilities. These eye care providers perform many of the functions outlined in points 2 and 3 but often have more time to dedicate to actively managed vision therapy practice compared with optometrists in hospital settings where vision therapy tends to be more home based.

Optometry is involved in at least one clinic or hospital setting, which sees patients with CVI in Israel, India and the UK. I would imagine there are many more and in many more countries than I am aware of at this time.

Professor Barry S Kran, OD, FAAO
Professor of Optometry, New England College of Optometry
Optometric Director, NE Eye Perkins Low Vision Clinic

From CVI Scotland:

Professor Kran advocates for greater understanding of CVI across his profession, including the creation of college electives and presenting at local, national and international meetings. He has also presented to and authored chapters and papers for interdisciplinary and educational groups involved in the care of individuals with CVI.

Professor Kran explains "Aside from the consideration of CVI as a diagnosis when vision function findings are not explained by a problem at the eyes, it must also be considered when there is a difference between vision function (acuity, contrast, field, etc) and how one functions visually. This includes a range of children with variably impacted vision function findings and an absence of ocular reasons for such behaviors to those with obvious ocular impairment but not sufficient to explain their level of difficulty in functioning visually or sustaining the use of vision for various activities such as learning or traveling through space.

Thus, the diagnosis of CVI may be appropriate in some children with good to excellent acuity but are not able to navigate space and/or find reading without masking or enlargement possible.

Professor Kran has been the optometric director of the collaborative clinic between the New England College of Optometry and the Perkins School for the Blind for the past 17 years. Aside from seeing the students at Perkins, two thirds of the patients seen at the clinic are children and adults who are visually and multiply impaired. Many patients are seen on referral from pediatric ophthalmologists, optometrists and vision educators specifically to provide clinical functional low vision services which includes the determination of the reason(s) for the visual impairment. Professor Kran and colleagues have recently begun a review of reports written since 2003 and have over 1500 reports which note CVI as a diagnosis. It is estimated that this represents 600 to 1000 unique patients.

Professor Kran, received the prestigious 2015 Allen Crocker MD Health Services award for a career devoted to helping children with disabilities and visual impairments. Click here for more information.

We are enormously thankful to Professor Kran for his hard work and dedication.


  • The World Council of Optometry definition of optometry, accessed 24 January 2018, please click here.
  • For information on curricula for optometry published by the World Council of Optometry, please click here.
  • "training and scope of practice of optometry varies from country to country" See the following link and the link to full document at this web page accessed 24 January 2018.
  • For a better understanding of what a functional or developmental optometrist is and how they can help children and adults with various vision issues, please visit

Professor Barry Kran


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At CVI Scotland we are devoted to helping people understand cerebral visual impairments, and together working towards developing the understanding of this complex condition.