Show more. (96)Get rights and content P. Tougne, H. Hommel, A.P. Legrand, N. Herlin, M. Luce, M. Cauchetier. DOI: /(96) Cite this publication + 2. André Legrand at École Supérieure de Physique et de Chimie Industrielles. André Legrand. (Pease et al., ; Leon and Legrand, ). Human-. derived al., ; Léon and Legrand, ). Research Letters 32(3):L

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There are three major types of congenital nystagmus; they will be described here only cursorily, because they have been treated in de- tail elsewhere. The aim of this study was to analyze i the variability of the HCV-4 subtypes, the route and source of HCV transmission and ii the influence of HCV-4 subtypes on their therapeutic response. A developing eye that is characterized by a low intraocular pressure and a relatively high scleral rigidity may remain small in diameter even if the genetic component is directed toward greater size.

Myopia, as we have discussed it here, is a developmental type of myopia. Size There is no direct evidence dealing with the size of the eye in a living human at birth or during the first 3 years of life. The disagreement is due to the inability of investigators to evaluate these contributions experimentally. Refraction and its components in twins. It is significant that even 0.

I have patients who are engineers and have this myopic condition increasing right up to their 50’s. During other times, while the eyes are open, there are usually at least two jumps per second. Am J Gastroenterol ; No one reported unilateral head pains.

Without such a description and ac- curate measurements from birth onward in the same persons, it legrans not possible to characterize completely the leegrand of the optical char- acteristics of the eye. For photographic reproducibility, the displacements and the arrows are larger than the jumps that occur during fixation. Saudi J Gastroenterol ; Averaged brain activity following saccadic eye movement.

In the eye, aberration, light scatter, and accommodative errors broaden the function further.


Hepatitis C virus infection in Egyptian volunteer blood donors in Riyadh. It is classified into the following corneal types: The row of circles simulates the time sequence of presentations to the brain of the chain of five successive central retinal views as the eye views the scene.

The two major changes are in accommoda- tion and in convergence. The motor type of congenital nystagmus is of genetic origin and is espe- cially common in males. The oldest experimental evidence is the phenomenon of flicker fusion, from which it can be argued that, if, at some particular flicker rate, flicker is not perceived, these chunks of intermittently presented information are subjectively smoothed in the same way as the chunks mediated by eye movements.

Another line of reasoning holds that, if eye jumps establish pack- ages of information, they should be followed by cortical activity marking the arrival of the packages. The absence of binocular vision and stereop- sis causes only minor problems in everyday life, and has no bearing on dyslexia. Give them a set of lenses that exactly correct their error. They con- cluded that no correlation could be found.

Thus, acceleration tends to turn the eyes to the side opposite the direction of gross movement of the head, and deceleration tends to turn the eyes toward the same side as the direction of movement of the head. The statements appear to be as valid as they were inand this concept, that the use of the eyes for near-work is responsible for the development of myopia, has a long history in ophthalmology and op- tometry, but there is inadequate evidence for supporting or rejecting it.

A few examples of continuous and discontinuous processes make the distinction clearer. Hepatitis C virus seroprevalence rate among Saudis. Ware described the effects of fitting concave or minus lenses to nearsighted persons as follows: The congenital or developmental variety is almost always horizontal and conjugate that is, manifest equally in the two eyes but varies for different directions of gaze. Some people show more change in error in this shift than others, and the usual error from this source is not small.

Excerpta Medica Foundation, We do not believe that puberty is an essential aspect. As has been stated many times, there are few myopes among school dropouts, and most school dropouts have good distance vision.


Legrand 03606 pdf

Hepatitis C virus subtypes circulating among intravenous drug users in Lisbon, Portugal. Habitual head-turn is thus a common presenting sign of this type of nystagmus. The bottom of the figure shows alternative tracks after the first two fixations, illustrating the stochastic na- ture of the process. Thus, if the entire environment moves relative to lerand observer, as in looking out of a train window or in an ideal optokinetic test, the eyes are compelled to follow the moving object.

Development of Optical Characteristics for Seeing end legran the first year.

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However, when legranc ability is statistically adjusted for, the correla- tion of refractive error and intelligence approximates zero. This vestibulogenic movement is normally present at birth, even in the premature infant, and may be elicited simply by rotating the infant in one’s arms. In the normal situation, clearly, the “com- puter” knows where the eyes are going to go next and, as a consequence, is able to get a good deal more out of the visual input from successive fixations than could otherwise be possible.

This article has been cited by 1 Meta-analysis Brittany E. Here the limit of negative contrast is 1. A well-known specialist has recommended “learning glasses” that would be plus llegrand lenses. But the evidence indicates that discrete areas of the brain have a degree of llegrand in effecting movements in response to particular stimuli, and it is conve- nient from a pedagogic point of view to emphasize this separateness. These findings indicate the need for optimal visual acuity in far-point tachisto- scopic training.

Rarely, however, do teachers give attention to the sensory or motor skills required for effec- tive far-point achievement. Fakeeh M, Zaki AM.