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
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Emmetropia.
em·me·tro·pi·a ( m  -tr  p - )n. The condition of the normal eye when parallel rays are focused exactly on the retina and vision is perfect. em me·tropic (-tr pk, -trpk) 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.
emmetropia
proper coordination of the refractive system and the focal length of the eyeball so that the focused image falls exactly on the retina.
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.
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