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Ophthalmology. In ophthalmology, horror fusionis is a condition in which the eyes have an unsteady deviation, with the extraocular muscles performing spasm-like movements that continuously shift the eyes away from the position in which they would be directed to the same point in space, giving rise to diplopia. Even when the double vision images ...
Prism correction is measured in prism dioptres. A prescription that specifies prism correction will also specify the "base". The base is the thickest part of the lens and is opposite from the apex. Light will be bent towards the base and the image will be shifted towards the apex.
Esophoria is an eye condition involving inward deviation of the eye, usually due to extra-ocular muscle imbalance. It is a type of heterophoria. Cause. Causes include: Refractive errors; Divergence insufficiency; Convergence excess; this can be due to nerve, muscle, congenital or mechanical anomalies.
Specialty. Neurology, ophthalmology. Diplopia is the simultaneous perception of two images of a single object that may be displaced horizontally or vertically in relation to each other. [1] Also called double vision, it is a loss of visual focus under regular conditions, and is often voluntary.
In this example the first eye, with a −1.00 diopter prescription, is the stronger eye, needing only slight correction to sharpen the image formed, and hence a thin spectacle lens. The second eye, with a −4.00 diopter prescription, is the weaker eye, needing moderate correction to sharpen the image formed, and hence a moderately thick ...
Examples of recordings are shown below: MR: sc (F) L/R 5∆ eso 8∆ (FR) MR: sc (F) L/5∆ eso 8∆ (FR) MR: sc (F) 5∆ BD 8∆BO (FR) sc: without correction - F: far - N: near - FR: fixing right - FL: fixing left - BD: base down prisms - BU: base up prisms - BO: base out prisms - BI: base in prisms - eso: esotropia - exo: exotropias
Aberrations of the eye. The eye, like any other optical system, suffers from a number of specific optical aberrations. The optical quality of the eye is limited by optical aberrations, diffraction and scatter. [1] Correction of spherocylindrical refractive errors has been possible for nearly two centuries following Airy's development of methods ...
Convergence insufficiency. Convergence Insufficiency. Other names. Convergence disorder. Specialty. Ophthalmology, optometry. Convergence insufficiency is a sensory and neuromuscular anomaly of the binocular vision system, characterized by a reduced ability of the eyes to turn towards each other, or sustain convergence .
Entoptic images have a physical basis in the image cast upon the retina. Hence, they are different from optical illusions, which are caused by the visual system and characterized by a visual percept that (loosely said) appears to differ from reality. Because entoptic images are caused by phenomena within the observer's own eye, they share one ...
Treatment options for esotropia include glasses to correct refractive errors (see accommodative esotropia below), the use of prisms, orthoptic exercises, or eye muscle surgery. The term is from Greek eso meaning "inward" and trope meaning "a turning".