ASSESSMENT OF VISION FOR
EDUCATIONAL PURPOSES
AND EARLY
INTERVENTION

Foreword

Assessment of vision in infants and children for early intervention and education has two main purposes: 1) to give basic information on visual functioning for selection of teaching/learning techniques or 2) to help in planning of early intervention. This text was written in early 1990s and used in East Africa and Ethiopia. Therefore many of the pictures are from different schools in Addis Ababa. Our framework in early intervention and education has changed since 1990s. Those days ‘Management of low vision in children’ (WHO 1993) was the text that we used as our guide. Its way of considering visual impairment and disability are close to the present International Classification of Functioning, Disability and Health (WHO 2007), Children and Youth Version which covers all functional areas.

Assessment of Visual Functioning (ICF 2001, ICF-CY 2007) or "Functional Vision"  is usually needed for decision whether the infant or child is eligible for early intervention, special services or special education. In most countries these services are limited to children who are at least moderately visually impaired. In some countries the child needs to be severely visually impaired or 'legally blind'.

As long as there was no internationally accepted classification of visual impairment for infants and children, many countries used classifications originally developed for workman's compensation. These old fashioned classifications are still used in many countries and States. The users do not seem to realise that vision cannot be assessed in young children as it is assessed in adult people and that the role of vision in the life of an infant and child is different from the role of vision in an adult person who loses vision.

Classification of visual impairment and disability has interested me ever since the first low vision clinic was opened in Helsinki in 1976 and I have written review articles on vision impairment since 1985 and on visual impairment in children during the last few years. The text on classification included here was a paper presented at the ICEVI European Conference in Cracow, July 9-13, 2000.

I will appreciate comments and suggestions on the question of eligibility. As I said after my keynote speech at the VISION99 in New York, the present strict adherence to 'legal blindness' when deciding on services leads to a situation where there are many 'illegally' blind children waiting for services that they need and deserve.

Functional Assessment is divided in three parts: Part I covers usual measurement techniques of visual functions. The text was written for the participants of the course in Addis Ababa in 1997 as a summary of my lectures. It is written for special educators and teachers who have a visually impaired child in their classroom and therapists who take care of visually impaired children. After reading this basic information and after having seen the slides in the introductory lecture, it will be possible to assess visual functioning of visually impaired children who do not have other handicaps complicating the use of vision.

Part II covers vision impairment in children with other impairments in hearing, motor functions or intellectual development. There is also a chapter on brain damage related vision impairment affecting higher visual functions.

Part III, written in 1998, covers vision impairment in infants and in children who after a disease or accident fall back on early developmental levels. This part of the contents will grow in near future more than the other parts because the area is under rapid development.

Part III also contains discussion on "The Untestable Child". Even if testing techniques have developed and we have specific tests for each age group, some children are and will be difficult to test. However, we should be able to make the decisions on early intervention and special education even in these cases.

Early intervention is often understood to mean (re)habilitation during the first year. Although a great majority of visual impairments occur before, during or soon after birth, there are also later disorders, infections, tumours, traumas, near drowning, inherited diseases etc. that cause an impairment in a child who may have seen normally or nearly normally during the first year. In that case, early intervention means supportive therapies and education started at the time of preliminary diagnosis, during treatment and continued after confirmation of the diagnosis. As during the first year, early intervention should be a part of diagnostic work and care at all ages of childhood.

When I started in vision rehabilitation in mid-70s, the concept 'early intervention' meant starting supportive measures at the age of three (3) years, before that age it consisted of parental counselling. There are still several countries where the children in age group 0-3 years are not given special education, a few countries where special education starts when the child comes to school at 5-7 years of age. In developing countries few visually impaired children go to school more than two years and even fewer have had special education.

To reiterate, early intervention means all the therapies and special education needed to help a child to enhance use of vision and to develop compensatory techniques in areas where visual information needs to be supported.

CONTENTS

PART I
Assessment of low vision in otherwise healthy children

1. Introduction
2.1. Screening-Groups of Visually Impaired Children
Screening procedure at the schools for the blind in developing countries
The Impact of Low Vision Project - Kenya In the Education of the Visually Impaired Children
Children without form vision
Children with form vision
2.2. Assessment
Case history
Structure of the eyes
Refraction and devices
Binocularity
Oculomotor functions
Visual acuity
Near vision acuity
Distance vision acuity
Reading acuity
Contrast sensitivity
Visual field
Demonstration glasses for training measurement of visual field
Colour vision
Visual adaptation
Compensatory functions
2.3. Interviews
2.4. Writing Summary of Evaluation/Assessment
Vision for communication
Vision for orientation and mobility
Vision for activities of daily life
Vision for sustained near vision tasks
Initiation of communication and action
2.5. Questionnaire (PDF-file)
The role of vision in the functions of a visually disabled child (PDF-file)


PART II
Assessment of low vision in children with other handicaps

1. Introduction
3.1. Assessment of vision in disorders affecting rod and cone cells including children with hearing impairment
Vision for communication
Cone adaptation problems
Illusory light phenomena
Suggested assessment routines
Typical behaviours to be recognised
4. Early vision loss due to rubella or a syndrome, in hearing and hearing impaired children
5. Visually impaired children with developmental delay
6. Visual impairment with motor impairment
7. Visual impairment and disability caused by brain damage
Levels of visual pathway lesions
The areas to be assessed
The "Sighted Blind"
8. Summary and report
Tests of the Lea Vision Test System


PART III
Assessment of vision during the first year and in children who remain at an early developmental level

9. Introduction
10. Causes of visual impairment/disability
11. Effect of visual impairment on the parents of the visually impaired infants
12. Typical features and assessment of vision development in visually impaired infants
0-3 months
4-6 months
Lighboxes in assessment and training/stimulation
Binocularity, strabismus, visual orientation in space
'Blindisms', stereotype behaviours
Compensatory modalities
7-12 months
Cognitive vision impairment
13. Children who become visually impaired and severely multihandicapped before school age
14. The Untestable Child