The character of eye movements in persons with weak vision differs sharply from those in norm. Two factors are especially significant: large amplitude eye oscillation and one-sided orientation of saccades. In medical practice such kind of eye movements is called nyystagmus: (Gudina O.N., 1963; Del'Osso F., 1983; Zee D.S., 1983; McCabe B.F.,1965; Ron S., Robinson D.A., Skavenski A.A., 1972).

Fig. 10 Records of patterns of eye movements in patients with weak vision: 1 - fixation of imaginary point (a man of 34 years old, diagnosis: optic atrophy after birth trauma); 2 -fixation of imaginary point (a man of 47, lost vision 26 years ago as a result of visual nerve damage); 3 - the same man under instruction "keep the eyes fully motionless"; 4 - fixation of fixed point ( a woman of 61, diagnosis: cataract, visual acuity - OD - 0,05; OS - 0,03; 5 - the same woman under instruction "keep the eyes fully motionless".

As an example can serve a recording of eye movements of a practically blind person, all saccades of the right eye of whom were directed in one way -to the right (fig. 10, record 1). The saccadic amplitude at that was in the range 0,4-1,2 angle/grade, an average interval between saccades was 0,4 sec. As we know this is a commonly encountered interval in norm despite the fact that the patient was practically blind all his life (34 years), he had common saccadic characteristics (amplitude and interval between them).

In cases when the loss of vision happened in mature age the eye movements had much in common with the norm. In particular, in a disabled veteran who lost his vision when he was 21 years old after 26 years distinct saccades were registered. They were synchronous for right and left eyes, there were 8 saccades in 8,4 sec with amplitude 12-45 angle/min, drift oscillation between saccades were within the norm, (record 2). The difference from the norm was only in saccadic orientation: most of saccades were oriented to the right (K=0,43).

As a rule asymmetry increases to the side where it was in the norm. In short, the process of asymmetry does not arise anew but intensifies under vision reduction. The experiments brought us to the conclusion: the worse the vision and therefore the more homogeneous visible sphere, the more saccadic generation is impaired. At that the aetiology of the disease is of no importance. The more significant factors are the degree of vision impairment and the duration of such a state.

According to vulnerability the mechanisms of maintenance of saccadic automaticity could be placed in the following way:
1. maintenance of saccadic symmetric orientation;
2. maintenance of saccadic minimal amplitude;
3. maintenance of intervals between saccades on the assigned level

Automaticity of saccades under myopia
Automaticity of saccades under blindness (ablepsia)
Automaticity of saccades under convergent and divergent strabismus
Automaticity of saccade under lesions of a muscle apparatus of eye
Automaticity of saccade under damage of oculomotor nerve
Automaticity of saccade under damage of brainstem structures
Alcohol influence on the automaticity of saccades
Mechanism of nystagmus