Characteristics of dynamic accommodation responses: comparison between the dominant and non-dominant eyes

Abstract

Accommodation responses of dominant and non-dominant eyes were compared in 18 healthy subjects aged 19-21 years to clarify the characteristics of dynamic accommodation. Internal targets were placed at -0.25 D and -4.0 D in an infrared optometer of a modified model, and external targets (brightness 30 cd/cm2, diameter 35 mm) identical in appearance with the internal targets, were placed 4.0 m and 0.25 m in front of the eyes. Three experiments were carried out by monocular viewing of the internal targets and monocular and binocular viewing of the external targets, and the results were compared between the dominant and non-dominant eyes. In viewing the internal targets, near-to-far responses were suppressed. In binocular viewing, the accuracy of accommodative position was increased, and the function of dynamic responses was improved. Furthermore, myopic shifts were observed in the near position after far-to-near accommodation and in the far position after near-to-far accommodation in the dominant eye compared with the non-dominant eye, and shortening of the response time and an increase in the response velocity were noted only in binocular viewing. These findings suggest that the dominant eye is in a tonic state and plays the primary role in far-to-near accommodation in binocular viewing.

The effect of 0.5% tropicamide/0.5% phenylephrine mixed eye drop in Chinese adults with myopia and its inter-eye difference in refractive outcomes

“…We speculate that during development the tonic state of the ciliary smooth muscle in the dominant eye might result in less accommodative accuracy or a greater lag of accommodation compared with that of the nondominant eye, leading to greater defocus. This might also explain why the dominant eye is more myopic 13 . In this study, there were 16.1% of subjects whose Diff M was greater than or equal to 0.50 D, which also meant that the response of the two eyes differed greatly toward cycloplegic treatment.…”

“…In a previous study, after instillation of 1% tropicamide in both eyes, researchers found no inter-eye response difference in spherical equivalent. However, there is some evidence supporting the existence of an aniso-accommodative response [12][13][14] . One study suggests that, under normal conditions, the dominant eye may be in a tonic state and may play a key role in accommodation 13 .…”

“…However, there is some evidence supporting the existence of an aniso-accommodative response [12][13][14] . One study suggests that, under normal conditions, the dominant eye may be in a tonic state and may play a key role in accommodation 13 . Moreover, there is some evidence supporting the existence of an aniso-accommodative response between the two eyes 13,14 .…”

“…One study suggests that, under normal conditions, the dominant eye may be in a tonic state and may play a key role in accommodation 13 . Moreover, there is some evidence supporting the existence of an aniso-accommodative response between the two eyes 13,14 . That being the case, one would speculate that bias is present in those studies where myopia development is evaluated by using data from only the right eyes.…”

“…In this study, the average sphere magnitude for the right and left eyes were À5.76 D and À5.56 D, which confirmed the existence of this ocular dominance since the right eye is usually the dominant eye. Retinal defocus (or the 'blur hypothesis') is a more recent hypothesis proposed to explain the development of myopia 13 . We speculate that during development the tonic state of the ciliary smooth muscle in the dominant eye might result in less accommodative accuracy or a greater lag of accommodation compared with that of the nondominant eye, leading to greater defocus.…”