Iridodonesis
Iridodonesis () is the vibration or agitated motion of the iris with eye movement. This may be caused by lens subluxation, the incomplete or partial dislocation of the lens; or by aphakia Aphakia is the absence of the lens of the eye, due to surgical removal, such as in cataract surgery, a perforating wound or ulcer, or congenital anomaly. It causes a loss of ability to maintain focus ( accommodation), high degree of farsightedn ..., the absence of a lens. The term originated from irido- () + doneo (, to shake to and fro). See also * Phacodonesis References External links * Ophthalmology {{eye-stub ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Lens Subluxation
Ectopia lentis is a displacement or malposition of the eye's lens from its normal location. A partial dislocation of a lens is termed lens subluxation or subluxated lens; a complete dislocation of a lens is termed lens luxation or luxated lens. Ectopia lentis in dogs and cats Although observed in humans and cats, ectopia lentis is most commonly seen in dogs. Ciliary zonules normally hold the lens in place. Abnormal development of these zonules can lead to primary ectopia lentis, usually a bilateral condition. Luxation can also be a secondary condition, caused by trauma, cataract formation (decrease in lens diameter may stretch and break the zonules), or glaucoma (enlargement of the globe stretches the zonules). Steroid administration weakens the zonules and can lead to luxation, as well. Lens luxation in cats can occur secondary to anterior uveitis (inflammation of the inside of the eye). Anterior lens luxation With anterior lens luxation, the lens pushes into the iris or ac ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Iris (anatomy)
The iris (: irides or irises) is a thin, annular structure in the eye in most mammals and birds that is responsible for controlling the diameter and size of the pupil, and thus the amount of light reaching the retina. In optical terms, the pupil is the eye's aperture, while the iris is the diaphragm (optics), diaphragm. Eye color is defined by the iris. Etymology The word "iris" is derived from the Greek word for "rainbow", also Iris (mythology), its goddess plus messenger of the gods in the ''Iliad'', because of the many eye color, colours of this eye part. Structure The iris consists of two layers: the front pigmented Wikt:fibrovascular, fibrovascular layer known as a stroma of iris, stroma and, behind the stroma, pigmented epithelial cells. The stroma is connected to a sphincter muscle (sphincter pupillae), which contracts the pupil in a circular motion, and a set of dilator muscles (dilator pupillae), which pull the iris radially to enlarge the pupil, pulling it in folds. ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Aphakia
Aphakia is the absence of the lens of the eye, due to surgical removal, such as in cataract surgery, a perforating wound or ulcer, or congenital anomaly. It causes a loss of ability to maintain focus ( accommodation), high degree of farsightedness ( hyperopia), and a deep anterior chamber. Complications include detachment of the vitreous or retina, and glaucoma. Babies are rarely born with aphakia. Occurrence most often results from surgery to remove a congenital cataract. Congenital cataracts usually develop as a result of infection of the fetus or genetic reasons. It is often difficult to identify the exact cause of these cataracts, especially if only one eye is affected. People with aphakia have relatively small pupils and their pupils dilate to a lesser degree. Causes Surgical removal of a lens, mainly in cataract surgery, is the most common cause of aphakia. Spontaneous traumatic absorption or congenital absence of lens matter is rare. Traumatic subluxation or disloca ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Phacodonesis
Phacodonesis (; ) is the tremulousness or vibration of the lens with eye movement. This is often due to lens subluxation, the incomplete or partial dislocation of the lens, caused by an injury to the eye in which some or most of the zonular fibers are broken. See also *Iridodonesis Iridodonesis () is the vibration or agitated motion of the iris with eye movement. This may be caused by lens subluxation, the incomplete or partial dislocation of the lens; or by aphakia Aphakia is the absence of the lens of the eye, due to ... References External links * Ophthalmology {{eye-stub ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |