ametropia


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Related to ametropia: astigmatism, myopia

ametropia

 [am″ĕ-tro´pe-ah]
an ocular disorder in which parallel rays fail to come to a focus on the retina. adj., adj ametrop´ic.

am·e·tro·pi·a

(am-ĕ-trō'pē-ă), Do not confuse this word with emmetropia.
An optic condition in which an error of refraction occurs such that with the eye at rest the retina is not in conjugate focus with light rays from distant objects, that is, only less distant objects are focused on the retina.
[G. ametros, disproportionate, fr. a- priv. + metron, measure, + ōps, eye]

ametropia

/am·e·tro·pia/ (am″ĕ-tro´pe-ah) a condition of the eye in which images fail to come to a proper focus on the retina, due to a discrepancy between the size and refractive powers of the eye.ametrop´ic

ametropia

(ăm′ĭ-trō′pē-ə)
n.
An eye abnormality, such as nearsightedness, farsightedness, or astigmatism, resulting from faulty refractive ability of the eye.

am′e·trop′ic (-trŏp′ĭk, -trō′pĭk) adj.

ametropia

[am′itrō′pē·ə]
Etymology: Gk, ametros, irregular, opsis, sight
a condition characterized by an optic defect involving an error of refraction, such as astigmatism, hyperopia, or myopia. ametropic, adj.

am·e·tro·pia

(am'ĕ-trō'pē-ă)
The optic condition in which there is an error of refraction so that with the eye at rest the retina is not in conjugate focus with light rays from distant objects, i.e., only less distant objects are focused on the retina.
[G. ametros, disproportionate, fr. a- priv. + metron, measure, + ōps, eye]

ametropia

Any deviation, in the relaxed focus of the eye, from the normal state in which distant objects form sharp and clear images on the RETINA. Ametropia may take the form of HYPERMETROPIA, MYOPIA or the meridional visual defect ASTIGMATISM. The state of normal refraction is called emmetropia.

ametropia 

Anomaly of the refractive state of the eye in which, with relaxed accommodation, the image of objects at infinity is not formed on the retina. Thus vision may be blurred. The ametropias are: astigmatism, hyperopia (hypermetropia) and myopia. The absence of ametropia is called emmetropia. Syn. refractive error; error of refraction; refraction (although not strictly correct since this term may also refer to the lack of ametropia). See hyperopic defocus; myopic defocus; refraction; refractive error; biological-statistical theory; emmetropization theory; nativistic theory.
axial ametropia Ametropia due primarily to an abnormal length of the eye while the refractive power is approximately normal (Fig. A8).
refractive ametropia Ametropia due primarily to an abnormal refractive power of the eye while the length is approximately normal. Refractive ametropias can be attributed to either an abnormal radius of curvature of the surfaces of the cornea, or the crystalline lens (curvature ametropia) or to an abnormal index of refraction of one or more of the ocular media (index ametropia).
Fig. A8 Emmetropia E, axial hyperopia H and axial myopia M. In emmetropia, parallel rays are focused on the retina. In hyperopia, the eye is relatively too short and the principal focus is behind the retinaenlarge picture
Fig. A8 Emmetropia E, axial hyperopia H and axial myopia M. In emmetropia, parallel rays are focused on the retina. In hyperopia, the eye is relatively too short and the principal focus is behind the retina

ametropia

the state when the image of a distant object is not in focus on the retina; due usually to some defect in the refraction of the optic system of the eye.
References in periodicals archive ?
De acuerdo con estudios realizados, aparentemente no existen diferencias por genero, pero estas pueden ser clarificadas una vez se conoce la edad de inicio de la ametropia y se realice su seguimiento y control (Johnson y Darwin, 2003).
Estos procesos predominan en las regiones de mayor extraccion de tejido por lo cual resultaria alli una ametropia postquirurgica.
Al determinar la concordancia en el estado refractivo, se observo que existe gran variabilidad entre los evaluadores asi como tambien en el tipo de ametropia, cuando se evalua con la retinoscopia dinamica monocular (22%) esto quizas debido a que no controla la acomodacion suficientemente y se genere alteracion en el diagnostico aun mas cuando son defectos con poderes dioptricos de esfera y cilindro bajos, lo cual contradice la afirmacion del autor en la que se refiere a que su tecnica supera la retinoscopia estatica binocular.
At baseline, children in the ametropia group scored significantly lower on the VMI and WPPSI-R, compared with the normal-vision group.
En relacion a los diagnosticos mas frecuentemente determinados, la ametropia ocupa el primer lugar (64,1 %), seguido de dislipidemia (57,8 %), obesidad I (50,0 %) e hipertension arterial (45,1 %).
Theoretical analysis of accom[logical not]modation amplitude and ametropia correction by varying refrac[logical not]tive index in PhacoErsatz.
Many suggestions have been given, one of such is the biological view which states that a moderate amount of ametropia is a normal variant caused by environmental and genetic factors in man16.
Made from Bausch & Lomb's patented silicone hydrogel material, balafilcon A, the PureVision Toric lens is indicated for the correction of refractive ametropia - that is, nearsightedness (myopia) and/or farsightedness (hyperopia) with astigmatism of up to 5.
Post-treatment increase in ametropia, anisometropia and / or irregular astigmatism can make the patient unhappy even though the cornea is clear and BCVA has improved (5,16) Refractive changes arise due to the location and extent of tissue removal from the cornea.
Ophthalmologist decides which procedure best suits the treatment needs of the patient, like LASIK (Laser-Assisted in situ Keratomileusis)/LASEK (Laser Assisted Subepithelial Keratectomy)/ PRK (Photorefractive Keratectomy), depending on the nature of ametropia, its intensity and the shape of the cornea.
Tambien se han revelado los valores de normalidad correspondientes a cada grupo de ninos, en funcion de la ametropia y en funcion de la edad, ya que no existe una base de datos normalizada para los parametros evaluados en menores de 18 anos.
Theoretical analysis of accommodation amplitude and ametropia correction by varying refractive index in Phaco-Ersatz.