In binocular viewing of real targets, the accommodative demand in the two eyes is not in general identical, yet the accommodation response in the two eyes is equal. In order to investigate how the accommodative signals from the two eyes are combined, this study has examined the effects of several forms of dynamic anisometropic stimulation on the accommodation response in both man and the rhesus...

Monocular Estimate Method Retinoscopy was used twice to measure the accommodative posture of 211 pre-presbyopic subjects. It was first measured with their farpoint lenses in place, and second, with the farpoint lenses and nearpoint plus lens additions (PLA) in place. The PLAs utilized for the second MEM were based on the binocular cross cylinder findings. The findings from the MEM-twice procedu...

AIMS Accommodation to overcome hypermetropia is implicated in emmetropisation. This study recorded accommodation responses in a wide range of emmetropising infants and older children with clinically significant hypermetropia to assess common characteristics and differences. METHODS A PlusoptiXSO4 photorefractor in a laboratory setting was used to collect binocular accommodation data from part...

Investigations into the progression of myopia in children have long considered the role of accommodation as a cause and solution. Myopic children show high levels of accommodative adaptation, coupled with accommodative lag and high response AC/A (accommodative convergence per diopter of accommodation). This pattern differs from that predicted by current models of interaction between accommodati...

PURPOSE At birth most, but not all eyes, are hyperopic. Over the course of the first few years of life the refraction gradually becomes close to zero through a process called emmetropisation. This process is not thought to require accommodation, though a lag of accommodation has been implicated in myopia development, suggesting that the accuracy of accommodation is an important factor. This rev...

PURPOSE The aim of this study was to investigate the changes in accommodation and binocular vision parameters during a period of 3 years and to evaluate their potential influence on the refractive changes observed over the same period of time in a population of university students in Portugal. METHODS A 3-year longitudinal study was conducted comprising 118 young adults (34 males and 84 femal...

PURPOSE Evidence exists for an additional inhibitory accommodative control system mediated by the sympathetic branch of the autonomic nervous system (ANS). This work aims to show the relative prevalence of sympathetic inhibition in young emmetropic and myopic adults, and to evaluate the effect of sympathetic facility on accommodative and oculomotor function. METHODS Profiling of ciliary muscl...

This paper provides an overview of recent results for relay-delay systems. In a first section, simple examples illustrate the problems induced by delays in the synthesis of sliding mode controllers. Then, a brief overview of the existing results shows the present advances and limits in this domain. The last parts of the paper are devoted to new results: first, for systems with state delay, then...

PURPOSE Less accommodation was found when human subjects read in blue (peak at about 440 nm) than when they read in red light (above 600 nm; [Kroger & Binder, British Journal of Ophthalmology 84 (2000) 890]). On the other hand, emmetropization in chickens did not appear to compensate for the chromatic defocus (385 nm versus 665 nm; [Rohrer, Schaeffel & Zrenner, Journal of Physiology 449 (1992) ...

In a recent paper we presented the first adaptive control design for an ODE system with a possibly large actuator delay of unknown length. We achieved global stability under full state feedback. In this paper we generalize the design to the situation where, besides the unknown delay value, the ODE also has unknown parameters, and where trajectory tracking (rather than equilibrium regulation) is...