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Hyperopia
Hyperopia Hyperopia (or more rarely, hypermetropia), also known as farsightedness or longsightedness, is a defect of vision caused by an imperfection in the eye (often when the eyeball is too short), causing inability to focus on near objects, and in extreme cases causing a sufferer to be unable to focus on objects at any distance. As an object moves towards the eye, the eye must increase its power to keep the image on the retina.
RELATED TERMS--------------------------------------
Hyperopia
Hyperopia (or more rarely, hypermetropia), also known as farsightedness or longsightedness, is a defect of vision caused by an imperfection in the eye (often when the eyeball is too short), causing inability to focus on near objects, and in extreme cases causing a sufferer to be unable to focus on objects at any distance. As an object moves towards the eye, the eye must increase its power to keep the image on the retina.
Farsightedness
Hyperopia occurs when the eyeball is too short from front to back, or the eye's focusing mechanism is too weak, causing light rays to be focused behind, rather than on the retina. People with hyperopia have difficulty seeing objects close up.
Vision
The sense of sight.
Eye
The organ of sight. The eye has a number of components. These components include but are not limited to the cornea, iris, pupil, lens, retina, macula, optic nerve, choroid and vitreous.
Retina
A membrane lining the inside of the back of the eye that contains light-sensitive nerve cells that convert focused light into nerve impulses, making vision possible.
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Hyperacidity
Excessive acidity.
Hyperacuity
Psychophysical tasks involving judgements of relative position that are about ten times finer than the separation of bars at the grating acuity limit.
Hyperacusis
Inordinate sensitivity to sounds; it may be on an emotional or an organic basis.
Hyperbaric
Characterized by greater-than-normal pressure. Hyperbaric oxygen is a therapeutic treatment designed to increase blood oxygen by delivering oxygen in a chamber room with greater-than-normal pressure.
Hyperchromasia
Excessive pigmentation.
Hypercolumn
A set of columns in the primary visual cortex (V1) that contains columns responsive to lines of all orientations from a particular region of space and for both eyes.
Hypercomplex cells
A third category of striate cells identified by Hubel and Wiesel that have since been classified as subsets of simple and complex cells. They posses inhibitory zones at one or both ends of oriented excitatory regions, thereby responding to bars of preferred orientation only if they are not too long.
Hyperemesis gravidarum
Excessive morning sickness.
Hyperemia
increased blood flow; may cause dental sensitivity to temperature and sweets; may precede an abscess.
Hyperesthesia
Abnormal acuteness of sensitivity to touch, pain, or other sensory stimuli.
Hyperfractionation
An increased number of smaller dosage treatments of radiation therapy.
Hyperglicemia
A condition in which the blood sugar is higher than normal.
Hyperglycemia
Too high a level of glucose (sugar) in the blood; a sign that diabetes is out of control. Many things can cause hyperglycemia. It occurs when the body does not have enough insulin or cannot use the insulin it does have to turn glucose into energy. Signs of hyperglycemia are a great thirst, a dry mouth, and a need to urinate often. For people with Type 1 diabetes, hyperglycemia may lead to diabetic ketoacidosis.
Hyperglycemic
High blood sugar.
Hyperglycemic hyperosmolar nonketotic syndrome
See Nonketotic Coma.
Hyperinsulinemia
The excess production of insulin. This is usually a consequence of insulin resistance in which the cells do not respond to insulin to reduce blood glucose levels.
Hyperinsulinism
Too high a level of insulin in the blood. This term most often refers to a condition in which the body produces too much insulin. Researchers believe that this condition may play a role in the development of noninsulin-dependent diabetes and in hypertension.
Hyperlipidemia
Too high a level of fats (lipids) in the blood.
Hypermobility syndrome
Syndrome of arthralgia associated with joint hypermobility.
Hyperorgasmia
The phenomenon of having an inordinate number of orgasms within a given period, as compared with a given criterion standard.
Hyperparathyroidism
Excessive secretion of parathyroid hormone from the parathyroid glands, which are situated alongside the thyroid gland in the throat, and which play a role in regulating the amount of calcium in blood and body tissues.
Hyperphilia
A condition or syndrome, variable in etiology and diagnosis, of being sexuoerotically above standard or inordinate, particularly with respect to some aspect of genital functioning prior to and at the acceptive phase. The condition of being supranormal in sexual and genital responsiveness or frequency.
Hyperphoria
A tendency for one eye to drift upward. A vertical type of muscle imbalance between the eyes.
Hyperpigmentation
Post-inflammatory hyperpigmentation is an excessive skin darkening at places where the skin was inflamed.
Hyperplasia
An increase in the number of cells in a tissue or organ, usually as a physiologic response to a stimulus.
Hypersensitivity
State of reactivity to antigen that is greater than normal for the antigenic challenge; hypersensitivity is the same as allergy and denotes a deleterious outcome rather than a protective one.
Hypersomnia
Excessive difficulty maintaining an alert awake state during the day, or undesired daytime sleep episodes. sleepiness, as evidenced by prolonged nocturnal sleep, ideas of reference The feeling that casual incidents and external events have a particular and unusual meaning that is specific to the person. This is to be distinguished from a delusion of reference, in which there is a belief that is held with delusional conviction
Hyperspadias
A congenital malformation or misplacement of the urethra as in hypospadias except that the position of the opening is on the upper or superior/dorsal surface of the penis.
Hyperstat
Hyperstat is a prescription or over-the-counter drug which is (or once was) approved in the United States and possibly in other countries. Active ingredient(s): diazoxide.
Hypertension
Higher blood pressure than normal. Diastolic blood pressure from 90 to 99 mm HG is considered mild hypertension; 100–109, moderate hypertension; and 110 or greater, severe hypertension. Systolic blood pressure from 140 to 159 mm HG is considered mild hypertension; 160–179, moderate hypertension; and 180 or greater, severe hypertension.
Hypertension (high blood pressure)
An arterial condition whose primary feature is chronically elevated blood pressure.
Hyperthermia
The treatment of cancers with heat.
Hyperthyroidism
Overproduction of thyroid hormone.
Hypertrophic Cardiomyopathy (HCM)
In this condition, the muscle mass of the left ventricle enlarges or "hypertrophies."
Hypertrophic obstructive cardiomyopathy (HOCM)
A bulge in the ventricle that causes impeded blood flow.
Hypertrophy
Over-development in size of an organ or of its constituent cells.
Hypertropia
A muscle imbalance in which one eye is straight and the other is turned upward.
Hypervariable regions
Portions of the light and heavy immunoglobulin chains that are highly variable in amino acid sequence from one immunoglobulin molecule to another, and that, together, constitute the antigen-binding site of an antibody molecule. Also, portions of the T-cell receptor which constitute the antigen-binding site.
Hyperventilation
Rapid or deep breathing producing faintness, numbness, chest pain, apprehension and tingling, and spasms of the extremities.
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Hypothalamus
The portion of the brain's limbic system that integrates incoming information, and either increases or decreases the release of certain hormones that instruct the pituitary gland to release hormones.
Human Immunodeficiency Virus (HIV)
A virus that steadily weakens the body's defense (immune) system until it can no longer fight off infections such as pneumonia, diarrhea, tumors and other illnesses. All of which can be part of AIDS (Acquired ImmunoDeficiency Syndrome). Unable to fight back, most people die within three years of the first signs of AIDS appearing. Most of all HIV infections have been transmitted through unprotected sexual intercourse with someone who is already infected with HIV. HIV can also be transmitted by infected blood or blood products (as in blood transfusions).
Hypertension
Higher blood pressure than normal. Diastolic blood pressure from 90 to 99 mm HG is considered mild hypertension; 100–109, moderate hypertension; and 110 or greater, severe hypertension. Systolic blood pressure from 140 to 159 mm HG is considered mild hypertension; 160–179, moderate hypertension; and 180 or greater, severe hypertension.
Hearing impairment
Complete or partial loss of the ability to hear, caused by a variety of injuries or diseases, including congenital causes. Limitations, including difficulties in understanding language or other auditory messages and/or in production of understandable speech, are possible.
Hemiplegia
Paralysis of one side of the body as a result of injury to neurons carrying signals to muscles from the motor areas of the brain.
Hyperopia
Hemophilia
A genetic blood disorder, almost always in males, in which blood does not clot properly as a result of an enzyme deficiency.
Hallucination
A false perception of something that is not really there. Hallucinations may be seen, heard, touched, tasted, or smelled by the ill individual. In schizophrenia, auditory hallucinations are most common.
Hydrocortisone
A hormone secreted by the adrenal cortex which affects
metabolism.
Hyperglicemia
A condition in which the blood sugar is higher than normal.
Hypoglicemia
A condition in which the blood sugar is lower than normal.
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