Purpose. To develop a mathematical tool for decomposition of comeal topographic data into comprehensive optical components. Methods. The polar data values arising from each mire of the TM>1 cornea1 topographer were separated into spherical (average power), regdar astigmatic (2’ harmonic), and non-regular astigmatic components (l’, 3’, and higher harmonics) by Fourier series analysis. Averages o...

Nocturnal bees, wasps and ants have considerably larger ocelli than their diurnal relatives, suggesting an active role in vision at night. In a first step to understanding what this role might be, the morphology and physiological optics of ocelli were investigated in three tropical rainforest species - the nocturnal sweat bee Megalopta genalis, the nocturnal paper wasp Apoica pallens and the di...

BACKGROUND The aim of the study is to raise the awareness of the influence of coma-like higher-order aberrations (HOAs) on power and orientation of refractive astigmatism (RA) and to explore how to account for that influence in the planning of topography-guided refractive surgery in eyes with coma-like-aberrations-dominant corneal optics. METHODS Eleven eyes with coma-like-aberrations-dominan...

Best-corrected acuity was measured for vertical and horizontal gratings and for Lea Symbols recognition acuity in 3- to 5-year-old children with high astigmatism and in non-astigmatic children. There was significant amblyopia among astigmatic children at baseline. There was no evidence that eyeglass correction of astigmatism resulted in a reduction in amblyopia over a 4-month average treatment ...

Neural changes that result from disruption of normal visual experience during development are termed amblyopia. To characterize visual deficits specific to astigmatism-related amblyopia, we compared best-corrected visual performance in 330 astigmatic and 475 non-astigmatic kindergarten through 6th grade children. Astigmatism was associated with deficits in letter, grating and vernier acuity, hi...

AIM 10 eyes of 10 patients are reported where progression of keratoconus in the host cornea occurred more than 10 years after penetrating keratoplasty with resultant increase in astigmatism. The technique and results of graft refractive surgery in seven eyes are presented. METHODS The clinical features and management of these patients were retrospectively analysed. Graft refractive surgery in...

OBJECTIVES To describe the refractive outcome of toric intraocular lens (IOL) implantation by comparing the postoperative refractive astigmatism with the preoperative keratometric astigmatism target. METHOD In a university department of a publicly funded hospital, 38 eyes of 29 patients underwent routine cataract surgery with insertion of a toric implant (SN60TT AcrySof Toric). Surgically ind...

Background: To determine the association between ocular dominance and myopic anisometropia in Chinese myopic subjects. This relevance would facilitate to identify the ocular dominance in bilateral cataract patients. Design: Retrospectively case study. Participants: 1503 Chinese myopic subjects, mean age 27 years, who were candidates for corneal myopic refractive surgery were reviewed between 20...

AIM The aim of this research was to evaluate vector analysis after implantation of toric intraocular lenses (IOLs) without deviation from the intended axis. METHODS The study included 18 eyes of 16 patients who underwent cataract surgery with the insertion of a toric implant (AcrySof IQ Toric). The postoperative IOL meridian placement completely corresponded to that planned. Using vector anal...

Purpose. To develop a mathematical tool for decomposition of comeal topographic data into comprehensive optical components. Methods. The polar data values arising from each mire of the TM>1 cornea1 topographer were separated into spherical (average power), regdar astigmatic (2’ harmonic), and non-regular astigmatic components (l’, 3’, and higher harmonics) by Fourier series analysis. Averages o...