PURPOSE To conduct a clinical validation of a virtual reality-based experimental system that is able to assess the spherical subjective refraction simplifying the methodology of ocular refraction. METHODS For the agreement assessment, spherical refraction measurements were obtained from 104 eyes of 52 subjects using three different methods: subjectively with the experimental prototype (Subj.E...

The refraction phenomenon at the interface of an ordinary material and a lossy metamaterial has been investigated. For oblique incidence on the lossy metamaterial, the planes of constant amplitude of the refracted wave are parallel to the interface and the plane of constant phases make a real angle with the interface (real refraction angle). The real refraction angle and hence, the real refract...

A longitudinal study of ocular refraction, position, and fixation was performed in children with a family history of strabismus. The children were examined at regular intervals between 3 months and 4 years of age, and the results are discussed in terms of changes in refraction between different ages and correlations between refraction and development of strabismus and amblyopia. Six of 34 child...

OBJECTIVE To evaluate the accuracy of noncycloplegic refraction compared with cycloplegic refraction in diagnosing refractive error in primary school children in southern Thailand. MATERIAL AND METHOD This is a cross-sectional study. One hundred twenty children aged from 6-13 years who had visual acuity of 20/40 or worse in at least one eye were included. All the children underwent autorefrac...

BACKGROUND It has been reported that exposure to artificial lighting at night during the first 2 years of life was very strongly associated with subsequent myopia development. METHODS The strength of this association was tested in a UK sample for the first time. The study population comprised 122 university students. RESULTS Myopia occurred with approximately equal frequency in those who sl...

INTRODUCTION To determine time trends in myopia over a 20-year period in Taiwan, we conducted 5 nationwide surveys pertaining to the ocular refraction of schoolchildren in 1983, 1986, 1990, 1995 and 2000. MATERIALS AND METHODS The sampling technique used herein involved the assessment of stratified systematic clusters, with the unweighted myopic rate being represented using data derived from ...

PURPOSE To examine the prevalence of refractive errors in children aged 3-6 years in China. METHODS Children were recruited for a trial of a home-based amblyopia screening kit in Guangzhou preschools, during which cycloplegic refractions were measured in both eyes of 2480 children. Cycloplegic refraction (from 3 to 4 drops of 1% cyclopentolate to ensure abolition of the light reflex) was meas...

Introduction. Previous cataract surgery studies assumed that first-eye predicted and observed postoperative refractions are equally important for predicting second-eye postoperative refraction. Methods. In a retrospective analysis of 173 patients having bilateral sequential phacoemulsification, multivariable linear regression was used to predict the second-eye postoperative refraction based on ...

BACKGROUND The USee device is a new self-refraction tool that allows users to determine their own refractive error. We evaluated the ease of use of USee in adults, and compared the refractive error correction achieved with USee to clinical manifest refraction. METHODS Sixty adults with uncorrected visual acuity <20/30 and spherical equivalent between -6.00 and +6.00 diopters completed manifes...