Training for vision testing

It is possible to start measuring recognition visual acuity values much earlier than we usually do by playing the test situation with the child as a part of the activities of an early intervention program, kindergarten, a school or at home. In the test situations the child uses either matching or naming so these important functions need to be trained.

Developing the concepts same and different

The LEA Puzzle was designed for 1) easy matching of basic colours and 2) matching of the forms that are used as the optotypes in the visual acuity tests. We learn to match colours before we learn to match forms. Playing with the puzzle pieces of the LEA Puzzle and matching their colours with the colours of the correct cutouts the child is also exposed to playing with forms. During this play you have an opportunity to observe eye-hand coordination, visual and motor memory of the location of the cutouts if the board is rotated 90 or 180 degrees. You also learn which strategy the child uses to rotate the “house” and the “apple” into correct orientation if these puzzle pieces are placed on the board rotated 90 degrees.  

As an introduction, the child can watch another child playing with the puzzle or you take the puzzle pieces out of their cutouts and the child places them back one by one. If the child is very young, you may need to let him watch the activity several times until the child shows interest to grasp the puzzle pieces and tries to put them in their cutouts.

Figure 1.

Figure 1. The puzzle is introduced to the child. The girl in these pictures has started to train for testing a few weeks earlier when she got her +6 spectacles for the first time. In such a situation it is important to learn whether the visual acuity values of the eyes are equal or has one of the eyes started to lose its resolving power, is on the way of becoming a ‘lazy eye’.

Figure 2.

Figure 2 A & B. To start, the easiest of the forms, the circle is placed in the middle of the puzzle board and the infant/ child is encouraged to find where it can be put. When the child has placed a puzzle piece in its cutout, respond with a positive calm remark confirming that “the piece got into its own place, the colour of the cutout is the same as that of the puzzle piece” (no clapping of hands). Then place the round puzzle piece on the table and give the next piece, the square.

In the beginning the puzzle pieces “house” and “apple” are first placed in the middle of the puzzle board in the same orientation as their cutouts. When the child has played with the Puzzle, you can place the puzzle pieces in a wrong orientation and watch, whether the child can plan the rotating movement. If this eye-hand coordination is difficult, you can use a short demonstration that includes also turning the puzzle pieces “house” and “apple” until they are in their correct orientations (“Now I must turn this puzzle piece to get it in its place.”). The hand movements may be difficult to copy so giving the child a model of the motor functions several times makes the play situation easier and thus more rewarding.

Figure 3.

Figure 3. When playing on the colourful side becomes easy, the black-and-white side is introduced if the child herself does not turn the puzzle board during play.

Children often memorise the locations of the puzzle pieces on the colouful side.. If you give a puzzle piece to a two-year-old child, she typically turns the colourful side of the puzzle piece up and then decides where the form should be placed.

The next step in the development is often difficult, may take weeks, months, even years. To understand that a picture is a representation of a three dimensional object may require a long period of drawing pictures of well-known objects. The next step in the development is often difficult, may take weeks, months, even years.

Figure 4.

Figure 4. The next level is to perceive the connection between a concrete form and its picture, first placing the puzzle pieces on large pictures, then on smaller pictures of the Single Presentation Flash Cards test or drawn by you.  

The play can be made challenging by turning the puzzle board 90 or 180 degrees when the child looks elsewhere. When the child is given the next puzzle piece by placing it on the centre of the puzzle board, the child usually starts to place it in the corner where the cutout has been before, stops in the middle of the movement, looks puzzled for a moment and then jubilant when she realizes that the puzzle board has been turned and the correct cutout is in a new location. You have collected important information of spatial memory and eye-hand-coordination.

If the large  pictures are slightly larger than the puzzle pieces, the task is easier than if the pictures are of the same size as the puzzle pieces. The key card that comes with many visual acuity tests can be used for matching.

Figure 5.

Figure 5. A. When matching the puzzle pieces with pictures of larger size has become easy, smaller and smaller pictures can be introduced. These smaller pictures can be drawn with the child watching or or of the Playing Cards are used. When the child is accustomed to look at the small pictures of the symbols, Playing Cards are used to measure visual acuity with single symbols. This test situation is much easier than the tests of visual acuity using line tests because there is no disturbing visual information around the optotypes. When near vision acuity is measured with single symbols, the name of the test is recorded in the test results, so that nobody assumes that the child has been tested with a line test.

Figure 6.

Measurement of visual acuity of each eye separately requires covering the other eye. There are different patches for this purpose. If the child has spectacles, a thin face tissue folded to a triangle is an efficient cover of an eye.

To understand that a picture can represent a three-dimensional object may require a long period of drawing pictures of well-known objects, like toys. If the pictures are slightly larger than the puzzle pieces, the task to see the similarity of the form of the puzzle piece and the picture is easy because the edge of the picture is visible next to the edge of the puzzle piece. The training cards that come with the LEA visual acuity tests can be used in training this phase of matching a concrete form with the picture of the same form. It may take a few days, weeks, months, sometimes several years until the concept of a picture representing an object develops.

Figure 7.

Figure 7. A - C. When you try to introduce the black-and-white side, the infant may immediately turn the puzzle board to the colourful side demonstrating that he is not yet ready to play with the more difficult side.

When playing on the black-and-white side, a typical two-year-old child turns the colourful side of a puzzle piece up and then decides where the form should be placed.

There is a great variation in the age for development of communication that is necessary during testing. Matching is the earliest response in many test situations. It requires the concept ‘same’, which may be present as sameness of colours toward the end of the first year if a typically developing infant has experienced play situations where objects are sorted in groups based on colours. This creates awareness of categories, a typical function of the visual system. Using this approach, children can learn to respond in testing of binocular visual acuity as early as at the age of 13 months.

If the child can learn the names of the forms as spoken words or signs, they can be used also in training because they will make the testing at the hospital much quicker than if matching is used. Any names are accepted, never “correct”. If the child hesitates when you ask, which names he would like to use for the symbols, you can give two alternatives (Would we today call this puzzle piece “window” or “TV”) but should not react negatively if the child prefers calling the square “brick”.

When playing with young children and children with developmental delays we should carefully choose our sentences to match the vocabulary that the infant/ child is accustomed to. If possible, use the dialect of the family and speak as closely like the parents or the therapist/ teacher of the child as you can. Sometimes it is wise to introduce the puzzle game to the parent or the therapist/teacher of the child and let them start the play. Many children have experienced frightening situations in hospitals where a new person was first nice and then did something painful so they are likely to be on guard not knowing what will happen next.

Since the training and observations may take weeks or months, they should be arranged as a part of the child’s normal play situations. The interpretation of the child’s responses may be difficult to the caretakers. Therefore video recording the child’s behaviours is usually helpful because the responses can be evaluated as many times as necessary by the vision rehabilitation team together with the child's therapist and/or teacher.