(n.) That refractive condition of the eye in which the rays of light are all brought accurately and without undue effort to a focus upon the retina; -- opposed to hypermetropia, myopia, an astigmatism.
Example Sentences:
(1) Of the adult aphakic cases, 80% were within 3 diopters of emmetropia at six months, with four cases showing an undercorrection.
(2) Seventy-three percent of the patients were within 3 diopters of emmetropia after surgery.
(3) We analyzed 450 consecutive cases of intraocular lens implantation (omitting only two inadvertent implantations in patients with high myopia) to determine the dioptric lens power in each case required to produce emmetropia.
(4) Fifty percent were within 2 diopters (D) of emmetropia and 92% within 3 D. All pediatric aphakic patients showed an improvement in best-corrected acuity, and 83% of eyes at 6 months were within 2 D of emmetropia; by 1 year a 3.4-D average myopic shift had occurred.
(5) At the time of entry into the USAF, refractive error data were clustered around emmetropia with a definite skew toward hyperopia.
(6) Twenty-one out of 43 eyes achieved refractive errors within 2 diopters (D) of emmetropia.
(7) The postoperative refraction and actually implanted IOL power were used to determine the IOL power needed for emmetropia.
(8) Eighty-three percent of eyes receiving intraocular lenses were within 2 D of emmetropia.
(9) The eyes of neonates grow from ametropia (refractive error) toward emmetropia.
(10) Further analysis demonstrated that results of unaided acuity and proximity to emmetropia were much better for low (< -2.87 D) and moderate (-3.0 to -5.87 D) than for high (> -6.0 D) myopes.
(11) Refraction showed 61.3% to be within 1 dioptre of emmetropia and 86.7% were within 2 dioptres.
(12) Although the optic-nerve-sectioned eye can sense the sign of a refractive error and initially adjust growth accordingly, it eventually overshoots emmetropia and reverses the sign of the initial refractive error.
(13) Contrary to previous reports, we do not find consistent high hyperopia in the rat, but rather refractions that range from near emmetropia (-0.12 D) to extreme hyperopia (+18.95 D).
(14) The predicted postoperative refraction was more accurate by modified SRK formulae, especially between emmetropia and myopia up to 0.5 diopters.
(15) The data are valuable to the intraocular lens surgeons, in that they demonstrate the range and frequency of intraocular lens powers needed to achieve emmetropia in a large population sample.
(16) At three years after surgery, 58% of eyes had refractive error within one diopter of emmetropia; 26% were undercorrected, and 16% were overcorrected by more than one diopter.
(17) Use of mean values in a theoretic artificial intraocular lens power equation suggests that aphakic dogs require an implant of approximately 40 diopters to achieve emmetropia.
(18) Multiple regression analysis was employed to estimate the amount of preoperative correction required to achieve emmetropia in 129 spherical radial keratotomy procedures.
(19) Three of 14 younger patients and 35 of 54 older patients were within 3 D of emmetropia.
(20) There was continuous changing of refraction towards emmetropia in all refraction groups.
Presbyopia
Definition:
() A defect of vision consequent upon advancing age. It is due to rigidity of the crystalline lens, which produces difficulty of accommodation and recession of the near point of vision, so that objects very near the eyes can not be seen distinctly without the use of convex glasses. Called also presbytia.
Example Sentences:
(1) The most common eye disease are cataract, refractive error and presbyopia, and diseases of the conjunctiva and sclera.
(2) In addition some individuals (7%) were found to develop early presbyopia.
(3) Their use for presbyopia, aphakia, and glaucoma is considered.
(4) Both the decrease in retinal illumination and the presbyopia accounted for only a trivial proportion of the acuity loss.
(5) Detailed understanding of these mechanisms and the environmental, dietary, and behavioural factors that may influence the development of presbyopia will require controlled studies and, in some cases, invasive experimental manipulations that can only be achieved through the use of an animal model.
(6) Diagnostic standards have a big practical importance in the ophthalmological geriatrics above all in glaucoma, apart from the presbyopia, which depends to the age in a big way.
(7) Complications, such as scarring from intersecting keratotomy incisions, irregular astigmatism resulting from multiple reoperations, and overcorrections with the attendant early onset of symptomatic presbyopia are becoming much less frequent.
(8) The results are described of a 10-year study of the longitudinal changes in the static response of an individual subject during the approach to absolute presbyopia.
(9) They present a variable refractive index which can be used to produce the necessary addition needed for presbyopia.
(10) The history of prostheses for presbyopia is reviewed with an account of the development of variable focus spectacles.
(11) All forms of ophthalmic correction for presbyopia require compromises in viewing flexibility and visual function.
(12) A 33-year-old white man developed premature presbyopia and anisocoria as initial manifestations of acute pandysautonomia.
(13) The corneoscleral incision could be made even smaller, the lens diaphragm would be conserved more physiologically, and a method of therapy for presbyopia might eventually be possible.
(14) The resulting data indicate significantly lower best-corrected distance visual acuities, a greater prevalence of many ocular pathologies, less frequent occurrence of myopia, and an earlier onset of presbyopia than is found in the general United States population.
(15) Is it true that environmental UVR is also the prime contributor in the deleterious lenticular changes that may begin with premature presbyopia, as has been postulated?
(16) The age at onset of presbyopia showed a slightly higher rate of concordance in the MZ than in the DZ pairs.
(17) Monovision, the use of a monocular addition for near viewing, is a clinical technique sometimes used to correct presbyopia.
(18) The genetic and environmental contributions to physical aging (hair graying, balding, presbyopia) and longevity (age at death) were examined by within-pair comparison in monozygotic (MZ) and dizygotic (DZ) twins in later adulthood.
(19) Presbyopia, cataract, and glaucoma are some of the visual constraints that may play an important role in making it difficult for the person to read the informed consent form.
(20) We have conducted two experiments to investigate the effect of monovision and other contact lens corrections for presbyopia upon peripheral visual acuity.