What's the difference between emmetropia and myopia?

Emmetropia


Definition:

  • (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.

Myopia


Definition:

  • (n.) Nearsightedness; shortsightedness; a condition of the eye in which the rays from distant object are brought to a focus before they reach the retina, and hence form an indistinct image; while the rays from very near objects are normally converged so as to produce a distinct image. It is corrected by the use of a concave lens.

Example Sentences:

  • (1) In the group of high myopia (over 20 D), the mean correction was 13.4 D. In the group with refraction between 0 and 6 D, 88% of the eyes treated had attained a correction between -1 and +1 D 3 months postoperatively.
  • (2) The third patient was using an extended-wear soft contact lens for correction of residual myopia.
  • (3) The yield of such studies may be high for an understanding of such diseases as myopia, retinal detachment, and keratoconus.
  • (4) Myopia ranged from -1.0 D to -9.0 D. Forty-two eyes (53%) achieved uncorrected visual acuity (VA) of 1.0 or better and 73 eyes (92%) better than 0.5.
  • (5) A 69-year-old patient with high myopia was treated with retrobulbar steroid injections.
  • (6) We have reported the development of 1.6 diopters of myopia in a group of patients exposed to reptitive oxygen breathing at two atmospheres absolute pressure.
  • (7) The X-chromosomal form is frequently associated with myopia.
  • (8) The progress of 108 children who were identified by the vision screening programme in school as having defective vision (excluding those with puberty onset myopia) was reviewed.
  • (9) Extraordinarily wide angles were observed in all cases and myopia was a common refractive error.
  • (10) The Houston Myopia Control Study is a 3-year randomized clinical trial in which each of 213 myopic children was placed in either a single vision (standard treatment) group, a +1.00 D add treatment group, or a +2.00 D add treatment group, on the basis of a randomized procedure.
  • (11) The term "instrument myopia" means an accommodative effort caused by the view into the microscope.
  • (12) During the first month the mean myopia gradually increased to 0.12 D more myopia and increased linearly to 0.50 D more myopia at 3 months.
  • (13) Expansion was not related to laser wavelength, patient age, SRNV size, or degree of myopia.
  • (14) Young adulthood myopia progression also appeared to be accompanied by a slight tendency toward a with-the-rule astigmatic shift.
  • (15) This association is comparable with subretinal neovascularization in high myopia, angioid streaks, choroiditis and choroidal ruptures.
  • (16) After prophylactic scleroplasty for high complicated myopia the patient developed bilateral detachment of the retina.
  • (17) The implications of these findings are discussed with regard to both current models of accommodation-vergence interaction and the etiology of late-onset myopia.
  • (18) To improve scleroplasty efficacy in children at a high risk of postoperative progress of myopia the authors have developed a new surgical method involving increase of the transplant size and its preoperative treatment with a foamy composition intended for filling the body cavities.
  • (19) In the present study, close ophthalmologic examinations were performed on 11 patients with FCMD, and we found myopia, weakness of the orbicularis oculi, congenital nystagmus, cortical blindness, optic atrophy, chorioretinal degeneration, etc.
  • (20) If the high myopias and cone dysfunction are considered to be parts of the same syndrome, the heredity could be x-chromosomal recessive or autosomal recessive.

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