Comprehensive medical care includes preventive, curative and rehabilitation medicine. In ophthalmology we usually talk about

• preventive ophthalmology or primary prevention,
• curative ophthalmology or secondary prevention of blindness and
• low vision rehabilitation or tertiary prevention of blindness.

All three aspects of prevention of blindness should be present in the work of each unit. However, in a number of ophthalmological centres the work is nearly solely curative forgetting the importance of primary prevention of diseases and disorders and the need of rehabilitative services also in ophthalmology.

The goal of low vision rehabilitation is to reduce the functional vision loss by enhancing the visual function through the use of different optical and non-optical devices and by compensating, substituting, the loss by the use of new skills and techniques based on other modalities.

Although low vision rehabilitation is concerned with the tertiary prevention of blindness, we need to have our eyes open for the possibilities of preventing and taking care of diseases. It is particularly important in the therapy and education of visually impaired children to notice any change in the child’s or young person’s condition. An impairment does not preclude the possibility of getting another disorder or disease that requires treatment, sometimes acutely.

So, if you see a school or preschool child deeply involved in knocking with his fist on forehead as if listening to something, remember that the child may be experimenting with flashing lights related to detachment of the retina and do not take it as a sign of mental problems. Ideally, we should always know about the possible new symptoms and signs that could occur in a disabled child whom we take care of. Also, we can include in the daily program of the children aspects of personal hygiene to prevent infections and teach them about prevention of accidents in play, games and sports. In our work we are thus involved with all the four important aspects: disorder, impairment, disability and handicap.

The word disorder covers structural changes caused by diseases and trauma. The structural changes may or may cause loss of vision so the diagnosis alone does not depict the impairment.

The impairment means the measurable changes in the different subfunctions of vision. The usual functions that are measured for the characterisation of impairment are visual acuity and visual field but also visual functions like contrast sensitivity, colour vision, visual adaptation to different luminance levels, diplopia etc. characterise the impairment. Often visual impairment is thought to be equal to impaired function of the eye. However, a lesion at any of the locations in the long visual pathway may cause visual impairment. Today, we do not have a good classification of visual impairment caused by changes in the function of posterior visual pathway and visual cortices or by disturbances in motor functions in vision.

The visual disability is assessed based on the use of vision in the four important functional areas of daily life: communication, orientation and mobility, activities of daily life (ADL) and sustained near vision tasks like reading and writing.

Since more than half of our visually disabled paediatric population has other disorders and disabilities, these need to be considered when ever we assess the child’s functioning. This is particularly important in the assessment of dual sensory impairment.

The words impaired and disabled seem to have strong emotional contents to a number of persons. Sometimes to the point that the word disabled or disability are abandoned and impaired or impairment used instead. It should be clearly understood that visual impairment as such is not interesting in rehabilitation, it is interesting in reporting for primary prevention of blindness and for need of therapeutic services whereas only when it causes disability it becomes a interesting question in rehabilitation.

The visual handicap is situation or task bound. A disability causes a handicap when it prevents the person from doing a task or makes it more difficult than it would be to a fully sighted or it interferes with participation in the different functions of the society.

In young children there is also an arrow backwards from visual impairment to visual disorder because of the pliability of the visual system. In these cases therapy functions also as treatment because it may bring considerable improvement in the visual functioning, more than would be possible through the age related development of vision without supportive therapy. This is an extremely important aspect of paediatric early intervention. Because of this possibility I would like to stress the importance of communication between all persons related to early intervention and education of these children.