Ectropion - loss of elasticity or control of the eyelid, usually the lower eyelid, that causes it to sag away from the EYE. Ectropion allows tears to overflow the lid rather than remaining in the eye. It also fails to protect the eye, and especially the CORNEA, permitting dryness and exposure to environmental particles that create irritation and possibly injury to the cornea and sclera (“white” of the eye).
Ectropion is a common symptom of BELL’S PALSY, a temporary paralysis of one side of the face that results from INFLAMMATION of the seventh cranial NERVE (facial nerve), and also may accompany neurologic disorders such as PARKINSON’S DISEASE and MULTIPLE SCLEROSIS.
With ectropion the eye feels irritated and scratchy. Tear production becomes excessive as the eye attempts to lubricate and protect itself, and tears typically run over the lip of the lid and onto the cheeks. The doctor can diagnose ectropion based on its appearance. Treatment is typically surgery to tighten the lid structure to permit the lid to stay against the eye. Whether the ectropion recurs depends on the underlying cause. Untreated ectropion may result in extensive damage to the surface of the eye and cornea, including INFECTION, that interferes with vision and the health of the eye.
Resource: Facts On File Encyclopedia Of Health And Medicine
Eye is the organ of vision. The paired eyes work in coordination to present NERVE impulses the BRAIN interprets as dimensional (stereovisual) images. The function of sight requires close integration among the structures of the eye, the neurologic system, and the muscular system. Each eye is a fluidfilled, elongated globe of fibrous tissue, about 1⁄4
Xanthelasma - deposits of fatty plaque that form blisterlike lesions on the eyelids, usually the upper eyelids near the corner of the NOSE. The lesions are yellowish in color and often indicate HYPERLIPIDEMIA (elevated BLOOD levels of cholesterol and triglycerides). Though harmless, the lesions can cause the eyelid to droop, obscuring vision when an upper
Vitreous Detachment - the separation of the vitreous humor, the gelatinous substance within the EYE, from the RETINA. Vitreous detachment commonly occurs with advancing age as the vitreous humor thins and takes on more of a liquid consistency. By itself vitreous detachment is harmless and has no effect on vision, though it typically produces FLOATERS
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Visual Acuity - the ability to see objects clearly and sharply. Visual acuity assesses central vision and represents the function of the CORNEA, iris (pupil size), LENS, and RETINA. The SNELLEN CHART, which presents lines of letters of diminishing size, is the standard measure of visual acuity. Environmental factors that influence visual acuity include
Visual Field - the total area or scope of vision. EYE care specialists map the visual field by measuring the boundaries of peripheral vision in degrees from the point of central vision. A normal field of vision is 135 degrees vertically (60 degrees up and 75 degrees down) and 160 degrees horizontally (100 degrees outward and 60 degrees inward). Everyone has
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Vision Impairment Definition Vision Impairment - the uncorrectable loss of vision. About 12 million Americans have vision impairments that prevent them from participating in occupations and activities that have requirements or legal standards for VISUAL ACUITY (the ability to see clearly) and VISUAL FIELD (the scope of peripheral vision). People who have
Uveitis - INFLAMMATION of the uveal structures of the EYE, which include the iris, ciliary body, and choroid. Uveitis most commonly affects the front of the eye (anterior uveitis) though may involve specific segments of the eye or the uveal tract throughout the eye (diffuse uveitis). Symptoms of Uveitis Symptoms can vary from mild to severe and may