BACKGROUND To evaluate the accuracy of an open-field autorefractor compared with subjective refraction in pseudophakes and hence its ability to assess objective eye focus with intraocular lenses (IOLs). METHODS Objective refraction was measured at 6 m using the Shin-Nippon NVision-K 5001/Grand Seiko WR-5100K open-field autorefractor (five repeats) and by subjective refraction on 141 eyes impl...

For decades the plasma physics community has relied on the approximation that the index of refraction of a plasma is due solely to the free electrons. This makes the index of refraction less than one and is an essential assumption used in energy deposition in the plasma as well as plasma diagnostics such as interferometers. Recent measurements of Al plasmas using X-ray laser interferometers hav...

Seventy years ago Steiger, a Swiss ophthalmologist, found the distribution of corneal powers to follow a normal (binomial) curve. He noted a wide range of values among emmetropes, and he also knew that their axial lengths varied significantly. He expected that normal distributions would be found for other components of refraction and also for refraction as a whole, and in seeking a controlling ...

Purpose. To investigate the changes of anterior segment after cycloplegia and estimate the association of such changes with the changes of refraction in Chinese school-aged children of myopia, emmetropia, and hyperopia. Methods. 309 children were recruited and eligible subjects were assigned to three groups: hyperopia, emmetropia, or myopia. Cycloplegia was achieved with five cycles of 0.5% tro...

The effect of brief periods of monocular oblique viewing on axial refractive error in myopes and emmetropes was studied in 20 normal subjects. Refractive error and higher order aberrations were measured either with the subject's head positioned such that the subject looked straight into an aberrometer with the right eye or the subject's head rotated to the right or left by approximately 30 degr...

PURPOSE Peripheral refraction is commonly used to infer retinal shape. Because of the different prevalence of myopia in the white compared with East Asian populations, peripheral refraction along the horizontal meridian was compared in white and East Asian young adults with emmetropic, low myopic, and moderately myopic refractive errors. METHODS Thirty-five white and 37 East Asian subjects we...

The molecular descriptors family on structure activity relationships methodology was applied on ten cyclic organophosphorus compounds in order to predict theirs molar refraction. A number of 107692 significantly different MDF members enter into a multiple linear regression analysis. A pair of descriptors (lGDmSMt, lAmrfEt), which have the best performing ability in prediction of molar refractio...

PURPOSE Axial length has been shown to explain up to 50% of the total variance in refraction, with axial length and refraction having a major genetic component. However, no study has attempted to determine whether the correlation between axial length and refraction is explained by shared genetic or environmental factors. METHODS All twins from Victoria aged 18 years or older were invited to p...

PURPOSE Ophthalmic technicians (OT) work at health facilities in Mozambique and are trained to provide primary and secondary eye care services including basic refraction. This study was designed to assess OT competence and confidence in refraction, and investigate whether an upskilling programme is effective in developing their competence and confidence at refraction. METHODS Thirty-one train...