emmetropia


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Related to emmetropia: ametropia

emmetropia

 [em″ĕ-tro´pe-ah]
the ideal optical condition, parallel rays coming to a focus on the retina. adj., adj emmetrop´ic.

em·me·tro·pi·a

(em'ĕ-trō'pē-ă), Do not confuse this word with ametropia.
The state of refraction of the eye in which parallel rays, when the eye is at rest, are focused exactly on the retina.
[G. emmetros, according to measure, + ōps, eye]

emmetropia

/em·me·tro·pia/ (em″ĕ-tro´pe-ah) a state of proper correlation between the refractive system of the eye and the axial length of the eyeball, rays of light entering the eye parallel to the optic axis being brought to focus exactly on the retina. Symbol E.emmetrop´ic
Emmetropia.

emmetropia

(ĕm′ĭ-trō′pē-ə)
n.
The condition of the normal eye when parallel rays of light are focused exactly on the retina and vision is perfect.

em′me·trop′ic (-trŏp′ĭk, -trō′pĭk) adj.

emmetropia

[em′ətrō′pē·ə]
Etymology: Gk, emmetros, proportioned, opsis, vision
a state of normal vision characterized by the proper relationship between the refractive system of the eyeball and its axial length. This correlation ensures that light rays entering the eye parallel to the optic axis are focused exactly on the retina. Compare amblyopia, hyperopia, myopia. emmetropic, adj.

em·me·tro·pi·a

(em'ĕ-trō'pē-ă)
The state of refraction of the eye in which parallel rays, when the eye is at rest, are focused exactly on the retina.
[G. emmetros, according to measure, + ōps, eye]
Enlarge picture
EMMETROPIA, MYOPIA, HYPEROPIA
Enlarge picture
EMMETROPIA, MYOPIA, HYPEROPIA
Enlarge picture
EMMETROPIA, MYOPIA, HYPEROPIA

emmetropia

(em?e-tro'pe-a)
The normal condition of the eye in refraction in which, when the eye is at rest, parallel rays focus exactly on the retina.
See: illustration; astigmatism; myopia

emmetropia

The state of the normal eye, with relaxed ACCOMMODATION, in which light rays from a distance (parallel rays) focus accurately on the retina giving perfect vision.

emmetropia

The refractive state of the eye in which, with accommodation relaxed, the conjugate focus of the retina is at infinity. Thus, the retina lies in the plane of the posterior principal focus of the eye and distant objects are sharply focused on the retina. This is the ideal refractive state of the eye. Note: the concept of emmetropia is not simple because accommodation is not inactive when fixating at distance (tonic accommodation). In fact, some authors consider hypermetropia of up to 1.00 D, in a pre-presbyope, as emmetropia. See resting state of accommodation; ametropia; conjugate distances.

emmetropia

proper coordination of the refractive system and the focal length of the eyeball so that the focused image falls exactly on the retina.
References in periodicals archive ?
Table 1: Mean AA in three groups Refractive status Number of patients Mean AA Emmetropia 37 10.
11 However, further refinements to the predictive accuracy of post-op emmetropia can be made.
This range is found to be closely correlated within the range of emmetropia where other values adjust to attain an optimum state of vision.
0) Table 4: Refractive errors by age group Age group Emmetropia Myopia Astigmatism Undetermined (years) 5-7 96 (96.
TABLE--5] of the 100 eyes studied 64 eyes had hypermetropia, 33 emmetropia and 2 eyes myopia.
of Eyes 6/6 80 6/9 3 6/12 2 6/18 5 6/24 5 6/36 3 PL + 1 PL - 1 Total 100 Eyes TABLE VI REFRACTIVE STATUS EYES Emmetropia 33 Hypermetropia 64 Myopia 02
In this context, emmetropia can be taken to mean a very small range of refractive errors around low hypermetropia.
Behndig A et al conducted a study and concluded that emmetropia (spherical equivalent -0.
Another inclusion criterion was that the aim of the surgery was emmetropia.
For patients who have enjoyed relatively good vision with near emmetropia all of their life, experiencing the vision change of presbyopia comes as a surprise.
On returning to distance vision, relaxation of the ciliary muscle allows the two lenses to come together again returning to emmetropia.
If the patient is self-funding, they could opt to have a clear lens exchange (CLE) on the other eye with emmetropia being the ultimate goal, but as this is not an option for NHS patients, the implant is calculated to reduce the risk of anisometropic problems.