Computer visual test is usually performed by the eye doctor in order to pre-identify Your defect. During this test, especially the astigmatism defect is determined precisely and normally better than by the doctor without this type of assistance.
You should preferably choose the center/optician with a good reputation, then You can be assured that the equipment for the test is modern and the results are reliable. But even if the results will not reflect the actual state to some extent, we should not be bothered by this, as we just want to know the scale of the defect for the exercise generator. I caution against performing such tests too often to check if our sight has improved. According to my knowledge, the test should be performed every half a year, or preferably after every year. To identify Your progress, You should not rely on the machine that is operated by the man (with various results). It is Your body, eyes and experience of a good vision that will tell You whether the applied techniques are giving good results. A Snellen chart placed in a room with permanent lighting will be enough to determine the progress in the correction of vision.
A print from the computer vision test should include the information on the defects, such as:
Short-sightedness and its magnitude (set numerically with the sign -)
Far-sightedness or presbyopia and its magnitude (set numerically with the sign +)
Astigmatism, its magnitude and axle in which it occurs (cylinder column)
Although I sincerely encourage You to use the above methods of visual defect identification, I am going to present the ways of this identification on Your own. It should be born in mind that the identification of the visual defect on Your own can be subject to considerable error, but we are not concerned with accuracy, rather with identifying the type and magnitude of the defect, which will allow to use our generator and generate the set of exercises.
Identification of the primary defect
Normally, there should be no problems with identifying the primary visual defect. If we have problems with reading from short distance, it means we suffer from far-sightedness (at the age of < 40) or presbyopia (at the age of > 40). If, however, our problems with vision occur at long distances, and we are not troubled by reading at short distance, it means we suffer from short-sightedness.
We will identify the primary defect more accurately with a Snellen chart set in the distance of 6 meters and attempting to read the series of letters in the row marked as 6m. If we do well with the reading, we are not troubled by short-sightedness. If, on the other hand, we are not able to see the letters in the row 20/20 (6m), we check which row of letters we are able to read. Assume that it will be the row marked as 20/40 (12m), which means that we have already developed a low short-sightedness – we can read the text from 6 meters, which is normally seen by healthy eyes from the distance of 12 meters. For the use of generator, You can assume that with the row of letters well visible 20/25 – 20/40 (low shortsightedness), 20/45 – 20/70 (medium shortsightedness), 20/100 – 20/200 (high shortsightedness).
The above test should be performed with each eye individually, which will allow to identify the differences in the defect between the eyes. In the case of a difference greater than one row on the chart, we have the defect of the “lazy eye”, that is, the amblyopia.
Identification of astigmatism
To determine the defect of astigmatism, we will use the figure of “astigmatic mirror”.
Use the figure on the screen or the mirror chart and look at them from distance where You see clearly the lines. If you have astigmatism, some lines seem to You darker, wider and make an impression as if they were farther away from each other. If all the lines are equally straight and black, You do not need to worry – astigmatism is not Your problem. Now, look at the astigmatic mirror from different distance, since some people have astigmatism only at certain distance. Naturally, the distance at which You look at the figure should ensure Your sharp perspective. Outside this area, the results are unreliable.
The astigmatic mirror is also an excellent figure to check Your progress in the correction of astigmatism. You can use it after each exercise for astigmatism to observe how the exercises affect the quality of vision.
Identification of the eye divergence
To identify the problems with eye convergence, we will use a cord or elastic line.
To check whether we have correct eye convergence and coordination, we attach one end of the cord to, for instance, the door, and hold the other end in the hand near the top of the nose, so as to tighten the cord. Place a few markers (such as beads) on the cord at equal distances. When You look at any bead, You should see the phantom lines that cross each other exactly where a bead is. Some people see these phantom lines with a bead as the sign of X, other as Y, and yet other as A. The shape is not as important as the perfect convergence of the lines in a bead. If the lines converge before or behind a bead, You have eye convergence disorder.
Now, look at the other beads checking eye convergence each time. If the phantom lines converge perfectly in each point, You do not need to worry – You are not troubled by the problems with eye convergence. If, however, you had such problems, do not worry. Vision convergence can be improved with the help of the exercises which we recommend to You.
The exercise above is a good mechanism to check whether the exercises for eye convergence give good results and how fast our vision gets back to normal condition.
Identification of the squint defect
In the case of large strabismus, the defect is visible enough to identify it. For a correct performance of exercises, it is important to define the type of squint, or the direction of the eye “escape”. In the case of small defects or a hidden squint, the person affected is often unaware of the defect. Therefore, everyone should examine himself/herself for this defect as its premature identification guarantees easier and faster recovery.
The simplest method to identify this defect is to consult the other person who will be able to determine quickly whether one of our eyes deviates to one of the sides. For the test, You should preferably use a book or chart, asking the examined person to observe a given word or letter. The chart should be placed about 20 cm from the face of the examined person and gradually moved away. At each distance, we carefully observe whether the eyes converge and one of them possibly squints.
You can also use the method of eye covering, covering alternately the left and right eye preferably with a piece of square sheet moved slowly from one side to the other. In the case of a hidden squint, the squinting eye manifests itself at the loss of the binocular vision, which can be observed looking at the eye behind the sheet.