Vision for Doing: Assessing Functional Vision of Learners who are Multiply Disabled
Chapter 7 Assessing Vision for Doing
Section 12 Responses to Objects
Aims of section 12
In this section you introduce objects moving in different directions in front of the learner. In this way you can ascertain if there are difficulties experienced in moving the eyes to follow objects. This would have important implications for positioning of materials.
How to usesection 12aMaterials to use>
It is best to use materials that have proved successful in other sections. You could for instance use a small torch, a highly contrasted object, or reflective object such as an unbreakable Christmas tree bauble. Refer to the first page of diagrams beginning this section.
What to observe
Refer to the diagram for 12a. The top half of the page shows a drawing of a face. In front of the face, at a distance of around 10 - 30 cm are two arrows. The arrow nearest the face (dashed lines) is split into two. One dotted arrow represents an object moving from the midline to the left and returning to the midline. The other dotted arrow represents movement from the midline to the right and back.
The arrow furthest from the face (continuous lines) represents an object moving across the midline from the right side to left and back across the midline. Make all movements slow and continuous.
In the bottom half of the page there is a room to insert the results of your observations. There are four rows in the box. Each row corresponds to one of the different kinds of movement described above. You will also see that the rows are divided into three columns - labelled smooth, jerky and none. You won't be surprised to learn that these correspond to the sort of eye movements the learner may make in following an object. These labels are very similar to what you used in earlier sections of Consistently, Occasionally and Never.
The last thing to note for yourself is whether the learner moves her
- head and eyes together;
- OR only eyes;
- OR only head.
You should treat 'only eyes' the same as 'head + eyes' (otherwise a learner who cannot turn her head because of physical disability would not be given credit for being able to see).
If, for each of the directions suggested, you are sure the movement has been followed smoothly, tick Smoothly. If inconsistent where she seems to catch sight of the object and then lose it and then fixate it again, tick Jerky . If the eyes did not follow the object, then tick Never.
How to use section 12b
For this diagram, instead of horizontal movement, there is vertical movement. The top half of the page shows the kind of movements to make with the object. Again the dashed lines represent stopping at the midline. The continuous lines represent movement across the midline.
The bottom half of the page offers a table for you to record the results of your observations in the same way as for 12a.
How to use section 12c
The last of the three diagrams in this section is for you to observe eye movements in response to objects moving in a circle and allows you to record results of your observations.
The top half of the page gives a diagram to show the kind of object movements to be made - clockwise and anti-clockwise. The bottom half of the page gives room to record the results of your observations.
Transferring results to Section 18:
As with the other sections, you now have to decide what the results of your observations mean for the Summary Chart in Section 18. In that Summary Chart, you will find that in the row for Section 12 there is only space to tick under Aware and Attend. The other three boxes are shaded, except for row 12c. Here you are allowed to Localise. Any general response by the learner to an object's movement in these directions cannot tell us more than that there is an ability to Attend.
Of course, if she makes a very specific response (eg; naming the object moving), this would mean she could Recognise through vision. Additional information will be needed if you are to tell that the learner is doing more than Localising. If you have that kind of extra information by all means tick boxes in the filled areas as appropriate.
No response to object movement?
If the learner Never shows any visual response to any of the four items in this section, try again on subsequent occasions with different objects and in different lighting conditions (that is in other Settings). You should at least try Section 13, 14 and 15. If she can walk or guide a wheelchair, try Section 17. If these, too, result in Never you should refer back to the curriculum suggestions contained in Sections 9, 10 and 11.
Or score Localise if:
the learner responds with Smooth eye movements to follow objects moving in all directions, including circular movements (for rows 12a, 12b, 12c). Tick in boxes for Localise in rows 12c, then move on to Section 13.
OR Score attend if:
you have ¡ Jerky eye movements to all directions. (This is as if she is trying to follow, attending to the object's movement, but is not quite able to do so). In this case, too, go to the Summary Chart, and tick in the boxes for Attend. Then move on to Section 13. You may still want to return to use the suggestions for curriculum development given in this present Section.
OR Score aware if:
the learner shows no Smooth responses, and only a few that are tick Jerky. If so, then tick Aware in the Summary Chart. Then move on to Section 13. In this case you may well want to return and use the curriculum suggestions given in this present Section.
If you are in any doubt as to whether you should tick Aware or Attend, choose Aware. You will certainly not lose out by doing this. If, by doing this, you make an error, results obtained in other sections will compensate.
Where to go now?
Having noted the results of your observations and transferred these to the Summary Chart, you are then ready to make a choice. The choice you make will depend on the results you obtained.
You can skip the remainder of this section and proceed directly to Section 13, dealing with assessment of visual fields. By doing this you will continue your assessment of use of Vision.
postpone further assessment and read the remainder of this section. In it we suggest activities for curriculum development.
To have an interest in this subject you will have found from the completed Summary Chart that the learner is only Aware through vision. For the checklist items you observed in this particular section, you may have found a few eye movements that were ticked Jerky. Similarly the learner's use of 'The Other Senses' will be functioning at the level of Awareness. Those most interested in this part of Section 12 will be working with people who have very severe difficulties in learning about the world.
Passive head movement
'Tracking' is the term commonly used to describe movements directed to follow objects, people and events. Where there is no tracking response, you may try passively to aid the learner's head movements. To try to separate out eye from head movement, you could try to gently hold the head, and see if you can elicit eye movements in the direction of a moving light source.
As horizontal movements are established earliest it is usually better to concentrate on these first.
It is also helpful to allow the learner to use other sensory information. For instance you could make a sound at the position of the light. There are many ways of doing this. For instance, you could move a cat bell along with the light source (use two hands as the light movement will then remain steady). Other examples are given under Improving Attending. Should the learner have strong 'likes', you may be able to use that preference in association with the direction of movement that is difficult. Or the learner could hold a torch as you move it from side to side. Or give verbal cues, smell or taste cues - or indeed any combination thereof. It may also be useful to associate a different combination of non-visual cues with different directions of movement.
Tonic neck reflexes
When engaging in training of tracking movements, it is important to remember that, for learners with some forms of cerebral palsy, separating head and eye movements may be difficult. To do so may well set off an asymmetric tonic neck reflex. Consult with a physiotherapist or occupational therapist, to determine correct positioning. As we mentioned earlier it may be possible to come to some sort of agreement on aiming to carry out this activity for very short periods. (This applies to all topics, it is certainly not confined only to Awareness).
You will be interested in this topic if you found that the learner responded to items of Chapter 7 at this level.
Tracking may be present in all directions but poorly sustained. Eye movements will typically not be smooth but jerky1.
Use of other senses
You will still be interested in pursuing the use of non-visual cues in association with visual cues. Another example is to allow the learner to hold a light source as it moves, giving verbal cues as well as the tactile cues. Contrast can be enhanced by carrying out finger play with cream spread on a mirror or table. Again try to use all of the senses other than just vision.
Range of objects
Use a range of objects. These might include balloons, puppets, wind up toys and bubbles.
This applies to other topics in this section. Long plastic tubes can be purchased. These give the impression of a light moving rapidly along a track. You can then arrange the tube so that the light appears to move in almost any direction. Beware of all disco lights which are based on the use of lasers. These should be avoided.
Refer to Section 10.
Use of computers
There is a range of software which may be useful in encouraging appropriate eye movements2.
As in the other sections you will be most interested in this topic if you have already carried out the items of Chapter 7 and found that the learner responded at this "level". In this case there may be a discrepancy in what the learner's general ability is from what their tracking ability is.
It may be helpful to associate a sound with the seen movement. Abnormal movement of the eyes may be evident in any of a number of ways. The eyes may not track the complete sweep of an object's movement, stopping at the midline even though the object has moved beyond this point.
Again you can try the non-visual associations described under Improving Awareness. Having done so you may find that it does not make any difference trying to associate sounds (or smells, or touch or any combination of these) with the visual component of the movement. The learner may never demonstrate such movements. But if you do not try, then this will certainly be the case.
Gradually change the non-visual cue so that it is given only at the point when the learner stops tracking the object. Watch closely to see the learner's response when one sounding object is replaced by another less familiar object.
If exhaustive attempts at associating visual with non-visual cues are indeed unsuccessful, you may be able to encourage the learner to make appropriate head movements in isolation from eye movements. This will help to compensate for the impoverished eye movements.
If compensation is the aim, use the sound at the point at which the learner appears to lose sight of the object. Encourage directional head movements with the sound source. As indicated, this can be also be carried out using olfactory or tactile information.
Play at throwing objects such as bean bags, fluorescent tennis balls, balloons, giving practice at following and catching moving objects under various lighting conditions, of bright sunlight (if you find any), shade, cloudy sky.
You will be interested in following up this part of Section 12 if tracking responses were not Smooth. As well as this the Summary Chart will have indicated the learner to function in other areas of ability at the "level" of Recognising. You therefore want to adjust your intervention techniques to suit someone at this "level".
All kinds of daily living activities are relevant to this topic. Familiar "objects" might be people; journeys to and from school or other location; food at mealtimes; and a host of others which you will find through experimenting in different Settings.
You will be interested in following up this part of Section 12 if tracking responses were not Smooth. Also the Summary Chart will have indicated the learner to be at the "level" of Understanding. You want to adjust intervention to suit.
You might also want to consider the following suggestions if the learner has difficulty in following the object (or light source) in any particular direction. The term "Vertical or horizontal gaze ophthalmoplegia" may have been used in medical records.
Here you will find that in one or more directions of object movement, the learner follows the movement quite smoothly. But in the other direction(s), tracking responses are absent. For instance he may track the object's path up from bottom to midline and then his eyes go no further. Or he may track from left to midline and midline to left but not midline on to right. There are of course a host of other possible combinations, too numerous to list individually.
Difficulties in vertical movement
In this case it is likely that there will be associated problems with mobility. You may notice the learner is uncertain in unfamiliar surroundings; experiencing problems when approaching changes in the surfaces of the ground. He will also have problems when confronted with lines of text or lines of pictures, drawings and symbols. Where the tracking problem is vertical, then shifting gaze to the next line after the end of the first line will be difficult. Copying work will be made easier if the piece to be copied is positioned to the side of the paper being copied.
Difficulties in horizontal movement
In contrast a problem in tracking objects in any horizontal direction will mean that work presented alongside will be made more difficult. Reading, which goes from left to right may be especially difficult. You may find the learner returning to the start of the line just read - especially when, as so often happens, there are associated short term memory problems. Partly this can be compensated for by the learner moving his head. This may have to be taught. It might help to place work for copying above or below.