• farsightedness
  • Also, the optometrist said that the reason he sees well without glasses is because the farsightedness and the astigmatism compensate for each other causing him to 'focus on zero' or focus on the retina so that there is little bluriness, and this would be why he has not complained about not being able to see. (medhelp.org)
  • correction
  • When the optometrist prescribed glasses for him, she also described astigmatism and expressed concern that if this condition were not corrected through use of glasses, he would have permanent vision loss by the time he was 9 or 10 years old (she was confident we had caught it in time to see complete or close to complete correction with lenses). (medhelp.org)
  • Astigmatism is a very important consideration when discussing surgical correction of refractive error with patients. (medscape.com)
  • The surgical correction of astigmatism was first attempted with astigmatic keratotomy, which is described in this article, along with compression sutures and wedge resection. (medscape.com)
  • 1) INITIAL BEST SPHERE CORRECTION A patient without astigmatism should be fully corrected after this step alone. (wikipedia.org)
  • Autofocusing and astigmatism correction in the scanning electron microscope (Doctoral dissertation, Faculty of the Department of Engineering, University of Cambridge). (wikipedia.org)
  • Cylinder
  • In with-the-rule astigmatism, the eye has too much "plus" cylinder in the horizontal axis relative to the vertical axis (i.e., the eye is too "steep" along the vertical meridian relative to the horizontal meridian). (wikipedia.org)
  • medical citation needed] In against-the-rule astigmatism, a plus cylinder is added in the horizontal axis (or a minus cylinder in the vertical axis). (wikipedia.org)
  • 2) SEARCH FOR Astigmatism The Jackson Cross Cylinder (JCC) is used in this step. (wikipedia.org)
  • cataract surgery
  • Astigmatic keratotomy was first performed in 1885, when Schiötz, a Norwegian ophthalmologist, treated a patient with 19.50 diopters (D) of astigmatism after cataract surgery with a 3.5-mm penetrating incision at the limbus in the steep meridian, which reduced the astigmatism to 7.00 D. (medscape.com)
  • Noel Alpins AM is an Australian ophthalmologist who developed the Alpins method of astigmatism analysis used in refractive, corneal, and cataract surgery, used in the research of LASIK (laser-assisted in situ keratomileusis). (wikipedia.org)
  • Post operative astigmatism following cataract surgery. (wikipedia.org)
  • amblyopia
  • I don't know what your childs prescription strength is but it takes a moderate amount of astigmatism to induce amblyopia. (medhelp.org)
  • 2. The visual system is developing between birth and ages 5-9 very rapidly and if during that time one or both eyes has a blurred image due to astigmatism it may develop permanently reduced vision (refractive amblyopia) which is not treatable, even with glasses, in the older child. (medhelp.org)
  • Definition
  • Importantly, the axes and magnitudes of external and internal astigmatism do not necessarily coincide, but it is the combination of the two that by definition determines the overall optics of the eye. (wikipedia.org)
  • keratoconus
  • It is, in fact, one of the exams the patients have to undergo prior to the Cross-linking and the Mini Asymmetric Radial Keratotomy (M.A.R.K.). For example, the KISA% index (keratometry, I-S, skew percentage, astigmatism) is used to arrive at a diagnosis of keratoconus, to screen the suspect keratoconic patients and analyse the degree of corneal steepness changes in healthy relatives. (wikipedia.org)
  • lenses
  • They work because their uniform front surface acts as the primary refracting surface of the eye, therefore correcting astigmatism without the control rotation mechanism of toric lenses. (mercola.com)
  • dr. hagan, Myself and my 7 yr old daughter wears lenses because we both are farsighted and have astigmatism. (medhelp.org)
  • Sources of this astigmatism include misaligned objectives, non-uniform magnetic fields of the lenses, lenses that aren't perfectly circular and contamination on the objective aperture. (wikipedia.org)
  • causes
  • When the optometrist discussed this condition with us, she said (something like)astigmatism causes blurriness which the brain then ignores because it cannot focus on that information, so effectively there would be blind spots. (medhelp.org)
  • Astigmatism causes difficulties in seeing fine detail. (wikipedia.org)
  • Near-sightedness results in far away objects being blurry, far-sightedness and presbyopia result in close objects being blurry, astigmatism causes objects to appear stretched out or blurry. (wikipedia.org)
  • incisions
  • [ 2 ] Faber, a Dutch ophthalmologist, performed perforating anterior transverse incisions in a 19-year-old patient with 1.50 D of idiopathic astigmatism, which reduced the astigmatism to 0.75 D and allowed him to pursue a career in the Royal Military Academy. (medscape.com)
  • [ 3 ] Lucciola of Terrin, Italy, was the first surgeon to use nonperforating corneal incisions to correct astigmatism. (medscape.com)
  • headaches
  • I am also confused because my son does not complain of eye fatigue, headaches, bluriness, or any complaint that I would associate with astigmatism. (medhelp.org)
  • vision
  • Astigmatism is a condition that results in blurred, unfocused, or fuzzy vision. (medicalcityhospital.com)
  • In a fast moving, high tech world of iPhones, iPads, smart-phones and computers, the demographic of ages 40 plus works later in life, the daily eye strain and acuity of mid vision and astigmatism becomes more and more critical. (thefreedictionary.com)
  • axis
  • In this case, astigmatism is observed even for rays from on-axis object points. (wikipedia.org)
  • In third-order astigmatism, the sagittal and transverse rays form foci at different distances along the optic axis. (wikipedia.org)
  • In the presence of astigmatism, an off-axis point on the object is not sharply imaged by the optical system. (wikipedia.org)
  • The amount of aberration due to astigmatism is proportional to the square of the angle between the rays from the object and the optical axis of the system. (wikipedia.org)
  • If an optical system is not axisymmetric, either due to an error in the shape of the optical surfaces or due to misalignment of the components, astigmatism can occur even for on-axis object points. (wikipedia.org)