(n.) A defect of the eye or of a lens, in consequence of which the rays derived from one point are not brought to a single focal point, thus causing imperfect images or indistinctness of vision.
Example Sentences:
(1) The authors have presented in two previous articles the graphic solutions resembling Tscherning ellipses, for spherical as well as for aspherical ophthalmic lenses free of astigmatism or power error.
(2) The high incidence of infant astigmatism has implications for critical periods in human visual development and for infant acuity.
(3) The most frequently occurring signs were: tilting of the disc (89%), oblique direction of the vessels (89%) and myopic astigmatism (96%).
(4) There was no evidence of glaucoma in any of the patients although two patients exhibited keratoconus and another one manifested moderate to high astigmatism.
(5) Of 809 eyes that underwent the Kelman phacoemulsification and aspiration (KPE) procedure, we report on 4 patients (0.49%) who developed sudden against-the-rule (AR) astigmatism after intraocular lens implantation.
(6) The two last methods are used for correction of astigmatism.
(7) The eyes were compared to 105 control eyes in which no astigmatic incisions were performed to assess the estimated effect of the TAK incisions.
(8) The choice of the method depends on the kind and degree of astigmatism and the degree of the spherical ametropia of the operated eye.
(9) The change in refractive astigmatism was as high as 1.50DC (diopter cylinder).
(10) The endpoint for the procedure is corneal astigmatism that will allow either spectacle or contact lens correction, depending on the patient's visual needs.
(11) A total of 527 astigmatic patients were examined for their axial distribution.
(12) Astigmatism greater than +1.25 diopters (as high as +5.50 diopters) was most commonly associated with dacryoceles (eight of 12 eyes) and with hemangiomas (14 of 17 eyes).
(13) In terms of the various keratometry values compared, mean K (corneal refractive power), flattest K, steepest K, astigmatism and the axis of astigmatism, 65% to 75% of the cases on automated keratometry were within 0.26 dioptres or 11 degrees of manually determined values; the difference was statistically significant (p < 0.001).
(14) Young adulthood myopia progression also appeared to be accompanied by a slight tendency toward a with-the-rule astigmatic shift.
(15) Forty-nine cases of primary keratophakia and 13 cases of secondary keratophakia were analyzed for postoperative astigmatism.
(16) A numerical example reveals some lesser known properties of the circle of least confusion of astigmatic pencils.
(17) Group II includes 10 patients with astigmatism due to circumscribed peripheral limbal corneal dystrophy.
(18) Amblyopia was due to anisometropia in 24 cases (50%), strabismus in 9 cases (18.7%), high astigmatism (meridional) in 7 cases (14.5%) and other causes or a combination of factors in 8 cases (16.7%).
(19) The differences between the 2 eyes were not statistically significant so far as the amount of astigmatism, final visual acuity, and peripheral anterior synechiae were concerned.
(20) Results showed that the wearing of spherical soft contact lenses, such as those used in this study, cannot be expected to predictably mask astigmatism.
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.