Accommodation-induced changes in iris curvature
نویسندگان
چکیده
منابع مشابه
Changes in corneal curvature during accommodation in chicks.
Evidence is presented for an active corneal component of accommodation in chicks. Using anesthetized chicks, consistent increases in corneal curvature were observed during accommodation produced either by electrical stimulation of the Edinger-Westphal nucleus or by topical application of 0.4% nicotine sulfate to the cornea. Electrical stimulation produced a mean accommodative amplitude of 9.2 d...
متن کاملOptically induced changes in the couplings between vergence and accommodation.
Vergence-induced accommodation (V-A) and accommodation-induced vergence (A-V) were measured in human subjects before and after they had worn various optical devices for 30 min. Laterally displacing periscopic spectacles, which increase the required change in vergence per unit change in accommodation, caused decreases and increases in the gain of V-A and A-V responses, respectively. These observ...
متن کاملNegative Gaussian curvature from induced metric changes.
We revisit the light or heat-induced changes in topography of initially flat sheets of a solid that elongate or contract along patterned in-plane director fields. For radial or azimuthal directors, negative Gaussian curvature is generated-so-called "anticones." We show that azimuthal material displacements are required for the distorted state to be stretch free and bend minimizing. The resultan...
متن کاملThe role of the iris in chick accommodation.
PURPOSE Peripheral defocus, higher-order aberrations, and accommodation interact with pupil size to influence retinal image quality and possibly eye growth. Iridectomy (ID) provides a fixed, enlarged pupil. Results from in vitro studies suggest that ID may reduce or eliminate accommodation in the chicken. This paper further investigates the effects of ID on chicken accommodation, eye growth, an...
متن کاملThe role of the iris in accommodation of rhesus monkeys.
After unilateral total iridectomy, maximum accommodation inducible by corneal iontophoresis of carbachol in rhesus monkeys was approximately 40% less in the iridectomized than in the contralateral untouched eyes, irrespective of age. Ultrasonographically measured anterior chamber shallowing and lens thickening were also less in the iridectomized eyes. Neither submaximal accommodation induced by...
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ژورنال
عنوان ژورنال: Experimental Eye Research
سال: 2008
ISSN: 0014-4835
DOI: 10.1016/j.exer.2007.10.023