OPHTHALMOLOGY

The Vitreous

Jan 23, 2019 by in OPHTHALMOLOGY Comments Off on The Vitreous

Introduction The vitreous body makes up approximately 80% of the volume of the eye and thus is the largest single structure of the eye ( Fig. 6.1 ). In the…

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Production and Flow of Aqueous Humor

Jan 23, 2019 by in OPHTHALMOLOGY Comments Off on Production and Flow of Aqueous Humor

In the healthy eye, flow of aqueous humor against resistance generates an intraocular pressure (IOP) of approximately 15 mmHg, necessary for the proper shape and optical properties of the globe. The…

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The Extraocular Muscles

Jan 23, 2019 by in OPHTHALMOLOGY Comments Off on The Extraocular Muscles

The extraocular muscles (EOM) are found within the bony orbit. They function in conjugate eye movements, maintenance of primary gaze position, and motor fusion – maintaining corresponding visual elements within…

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Neural Control of Eye Movements

Jan 23, 2019 by in OPHTHALMOLOGY Comments Off on Neural Control of Eye Movements

Introduction Three fundamental visual sensory-motor tasks The neural control of eye movements is organized to optimize performance of three general perceptual tasks. One task is to resolve the visual field…

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Three-Dimensional Rotations of the Eye

Jan 23, 2019 by in OPHTHALMOLOGY Comments Off on Three-Dimensional Rotations of the Eye

Eye motility In principle the eyeball, like any rigid object, has six degrees of freedom: three for rotation, and three for translation. The adult human eyeball is about 24–25mm in…

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Cornea and Sclera

Jan 23, 2019 by in OPHTHALMOLOGY Comments Off on Cornea and Sclera

Introduction The outermost, fibrous tunic of the human eye is the cornea and the sclera ( Fig. 4.1A,B ). Both are soft connective tissues designed to provide structural integrity of…

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Accommodation

Jan 23, 2019 by in OPHTHALMOLOGY Comments Off on Accommodation

Introduction “There is no other portion of physiological optics where one finds so many differing and contradictory ideas as concerns the accommodation of the eye where only recently in the…

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Optical Aberrations and Wavefront Sensing

Jan 23, 2019 by in OPHTHALMOLOGY Comments Off on Optical Aberrations and Wavefront Sensing

Introduction Myopia, hyperopia and cylinder are refractive errors known as second-order aberrations. These aberrations result in the inability of the eye to focus images appropriately on the retina. In myopia,…

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Optics

Jan 23, 2019 by in OPHTHALMOLOGY Comments Off on Optics

The young eye Primate and human infants must normally pass head first through their mother’s pelvis to accommodate the limited opening determined by the bony configuration. Therefore the size of…

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Disorders of the Eyelids

Jan 21, 2019 by in OPHTHALMOLOGY Comments Off on Disorders of the Eyelids

Definitions and Epidemiology Print Section Listen The most common eyelid abnormality in children is ptosis (blepharoptosis), which causes drooping of the eyelid. The upper eyelid normally rests just below the…

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