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  2. Craniopharyngioma - Wikipedia

    en.wikipedia.org/wiki/Craniopharyngioma

    A craniopharyngioma is a rare type of brain tumor derived from pituitary gland embryonic tissue [1] that occurs most commonly in children, but also affects adults. It may present at any age, even in the prenatal and neonatal periods, but peak incidence rates are childhood-onset at 5–14 years and adult-onset at 50–74 years. [2]

  3. Nelson's syndrome - Wikipedia

    en.wikipedia.org/wiki/Nelson's_syndrome

    Melson's syndrome is a disorder that occurs in about one in four patients who have had both adrenal glands removed to treat extreme slackness. [1] In patients with pre-existing adrenocorticotropic hormone ()-secreting pituitary adenomas, loss of adrenal feedback following bilateral adrenalectomy can trigger the rapid growth of the tumor, leading to visual symptoms (e.g. bitemporal hemianopsia ...

  4. Farsightedness - Wikipedia

    en.wikipedia.org/wiki/Farsightedness

    Far-sighted vision on left, normal vision on right Human eye cross-section A diagnosis of far-sightedness is made by utilizing either a retinoscope or an automated refractor-objective refraction; or trial lenses in a trial frame or a phoropter to obtain a subjective examination.

  5. Adjustable-focus eyeglasses - Wikipedia

    en.wikipedia.org/wiki/Adjustable-focus_eyeglasses

    Distance vision corrections are made by re-adjusting the lens for distance, instead of by tilting and/or rotating the head to view object through the best part of the lens for the distance. Adjustable focus lenses, like single-focus lenses, also reduce image-jump and spatial distortion in the field of view associated with traditional multi ...

  6. Corrective lens - Wikipedia

    en.wikipedia.org/wiki/Corrective_lens

    Single vision lenses correct for only one distance. If they correct for far distance, the person must accommodate to see up close. If the person cannot accommodate, they may need a separate correction for near distances, or else use a multifocal lens (see below). Reading glasses are single vision lenses designed for near work and include over ...

  7. Visual acuity - Wikipedia

    en.wikipedia.org/wiki/Visual_acuity

    A person's visual acuity is registered documenting the following: whether the test was for distant or near vision, the eye(s) evaluated and whether corrective lenses (i.e. glasses or contact lenses) were used: Distance from the chart D (distant) for the evaluation done at 20 feet (6 m). N (near) for the evaluation done at 15.7 inches (400 mm).

  8. List of instruments used in ophthalmology - Wikipedia

    en.wikipedia.org/wiki/List_of_instruments_used...

    Charts for vision - •Distant vision: to determine visual acuity of distant vision ••Snellen's distant vision chart-do-; for those who can read in English ••Regional language charts-do-; for those who can read in their local language ••E Chart-do-; for those who can not read ••Landolt's broken ring chart-do-; for those who can ...

  9. Prolactinoma - Wikipedia

    en.wikipedia.org/wiki/Prolactinoma

    A prolactinoma is a tumor of the pituitary gland that produces the hormone prolactin.It is the most common type of functioning pituitary tumor. [1] Symptoms of prolactinoma are due to abnormally high levels of prolactin in the blood (hyperprolactinemia), or due to pressure of the tumor on surrounding brain tissue and/or the optic nerves.