To summarise and describe visual and vision related functions that are assessed in children with other impairments and disabilities, information needs to be obtained both from the doctor and from the observations of the vision team.

Information from the doctor:

  • structure of the eyes and visual pathways: what can be expected in terms of visual field and quality of central vision
  • refraction and how the refractive error has been corrected/overcorrected
  • visual sphere of the child
  • how the glasses/contact lenses affect the visual sphere
  • which other impairments/disabilities the child has
  • how do they affect the use of vision
  • results of all clinical measurements, with explanation
  • if the nature of the lesion is well known, a description of it

All these facts are not available in each case, e.g. refraction may be impossible to measure objectively when the optic media are cloudy. It may require a long period of observation and trials with different glasses until the child is older and can answer questions. The concept of the visual sphere is not a concept commonly recognised as yet.

In developing countries medical information may not be available. Only some parts of it can be determined by direct observation. This makes the assessment far more difficult than when it is based on good clinical information.

Children functioning at or above the level of 3-4 years

  • reassess the basic visual functions using appropriate tests
  • if the results differ from those of the clinical evaluation, discuss the results with the child's doctor
  • find out how the child uses vision in the four main functional areas: communication, orientation and mobility, activities of daily live (ADL) and sustained near vision tasks,
  • if the child has both peripheral (i.e. eye and/or anterior pathway disorder) and central (i.e. brain damage related) changes in vision, try to define how each of them affects the child's functioning.
  • together with the parent(s), therapist(s) and teacher(s) try to answer questions on how much vision affects each of the four main areas of functioning:

- Communication: the distances at which the child can perceive visual communication with the most important persons, effect of luminance level, any specific difficulties in recognition of faces, expressions, body language; is there enough sight to make the child initiate communication or is initiation of communication solely based on auditory information?

- Orientation and mobility: how far the child can recognise landmarks, use of scanning techniques, and use of low contrast information? Is there photophobia or do twilight situations cause problems? How good is the use of other senses and memory? Are there any signs of specific problems in spatial awareness or orientation in space? Special group: the orientation and independent mobility of children using wheel chairs requires specific attention.

- Activities of daily life: participation in age appropriate activities, location and finding objects of interest, self feeding, grooming, "working" distances, head posture, eye-hand co-ordination, observe ball and other games - use of visual field and scanning for ADL.

- Sustained near vision tasks: sizes of details perceived and those missed in pictures and texts, structure of visual field for near vision tasks, variation in visual function in near vision tasks, possible role of insufficiency or spasms of accommodation, use of optical and non-optical devices, ergonomics in all activities but especially at the computer and CCTV, needs for special techniques because of motor problems in oculomotor functions or hand functions, effect of posture.

When a child has a progressive disease, both the present situation and the changes in the child's capabilities in the foreseeable future need to be anticipated and provided for.

The assessment continues in the classroom, during physical education and mobility instruction, during homework and hobbies. Children with severe motor disability who are in special schools often need to get specific attention in the execution of the (re)habilitation plans because visual problems may not be thoroughly understood by the teachers and therapists specialised in motor impairment and communication problems. However, with further basic education, the assessment teams at these schools and special day care centers become very effective co-workers with the vision team and can be very creative in modifying the child's supportive devices to facilitate oculomotor control and optimal use of vision.

Psychologists at all schools and also at the hospitals need to be fully aware of the visual content of their testing materials and together with the vision team choose tests which are not adversely influenced by the vision impairment of a particular child or where the influence can be understood. The materials should also be modified to fit the experiences of visually impaired children. Presently, too many visually impaired children are evaluated as functioning at a much lower cognitive level than they actually are. Their experiences of the world are not understood and the test materials may be close to the threshold of visual function or even below it, so that the child responds to other information than what is thought to be available. If the psychologist can be present during most of the functional assessment of vision, it will help him/her to modify the test situations and integrate them as an adjunct to the evaluation of visual function.

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