(n.) The science of the refraction of light; that part of geometrical optics which treats of the laws of the refraction of light in passing from one medium into another, or through different mediums, as air, water, or glass, and esp. through different lenses; -- distinguished from catoptrics, which refers to reflected light.
Example Sentences:
(1) Dioptric aniseikonia was calculated between 1 month and 24 months after surgery (with Gruber's and Huber's computer program) on the basis of most recently obtained values (bulb axis length, depth of the anterior chamber, lens thickness, necessary refraction), and compared with subjective measurements taken with the phase difference haploscope.
(2) Accommodation measurements of nine young, emmetropic subjects were obtained with an infrared optometer while they viewed superimposed horizontal and vertical square-wave gratings at various dioptric separations.
(3) The relationships between dioptric blur, pupil size, retinal eccentricity, and retinal sensitivity were investigated in the central 5 degrees of the visual field in 10 normal subjects using the Humphrey Field Analyzer.
(4) inhomogenities in the dioptric media, reflections at refracting surfaces, diffraction at the pupil borders, and the distribution of scattered light in the retina it becomes possible to develop indications for the construction of a focal optical stimulator.
(5) The elements of the dioptic power matrix have previously been interpreted in terms of power along particular meridians with the off-diagonal elements interpreted as a new form of dioptric power called torsional power.
(6) If the positions of the principal points of the crystalline lens are conjectured, its equivalent power and that of the eye can be calculated as described from ocular dioptrics.
(7) These ultra-thin soft lenses have proved extremely successful in case of visual defects ranging from - 16,0 to + 16,0 dioptrics.
(8) The dioptric elements in each ommatidium consist of a laminar cornea, which is flat externally and convex internally, and a bipartite crystalline cone.
(9) An alternative method for evaluating lens resolution is to determine the resolution efficiency (the relative percentage performance of a lens compared to a diffraction-limited lens of the same dioptric power).
(10) The former figure has the dioptric value M X sin2 alpha, the latter M X cos2 alpha.
(11) We analyzed 450 consecutive cases of intraocular lens implantation (omitting only two inadvertent implantations in patients with high myopia) to determine the dioptric lens power in each case required to produce emmetropia.
(12) The analysis contains four diagrams: a plot of the raw keratoscope data for quality control, a three-dimensional wire model of corneal surface power distribution, a plot of dioptric point surface powers, and a color-coded contour map of corneal surface powers.
(13) The eyelid fusion was temporarily cut and opened at about five-month intervals, and the dioptric power and axial length of test and control eyes were measured.
(14) Using both our own and published data, we compared the effects of diffusive blur, dioptric blur, and eccentric viewing on contrast sensitivity for letter and grating targets.
(15) They produce a magnified image, but it is an image that suffers from significant dioptric blur, diminished somewhat by use of a peep sight in the bowstring which functions as an aperture stop.
(16) The dioptric apparatus of each ommatidia includes a biconvex corneal lens and a spherical crystalline cone that is secreted by two cone cells.
(17) The eye consists of about 3600-3700 ommatidia, each containing a dioptric apparatus formed by a lamellated corneal lens and a eucone-type crystalline cone.
(18) We defined the depth of focus at a given spatial frequency to be the dioptric range for which the modulation transfer exceeds 50% of its peak value.
(19) Dioptric blur had a strong negative effect on Snellen acuity, consistent with previous studies, but had little effect on grating acuity.
(20) Methods are described for testing hypotheses on mean dioptric power and on variance-covariance of dioptric power for one and more than one population.
Lens
Definition:
(n.) A piece of glass, or other transparent substance, ground with two opposite regular surfaces, either both curved, or one curved and the other plane, and commonly used, either singly or combined, in optical instruments, for changing the direction of rays of light, and thus magnifying objects, or otherwise modifying vision. In practice, the curved surfaces are usually spherical, though rarely cylindrical, or of some other figure.
Example Sentences:
(1) These results demonstrate that increased availability of galactose, a high-affinity substrate for the enzyme, leads to increased aldose reductase messenger RNA, which suggests a role for aldose reductase in sugar metabolism in the lens.
(2) Based on several previous studies, which demonstrated that sorbitol accumulation in human red blood cells (RBCs) was a function of ambient glucose concentrations, either in vitro or in vivo, our investigations were conducted to determine if RBC sorbitol accumulation would correlate with sorbitol accumulation in lens and nerve tissue of diabetic rats; the effect of sorbinil in reducing sorbitol levels in lens and nerve tissue of diabetic rats would be reflected by changes in RBC sorbitol; and sorbinil would reduce RBC sorbitol in diabetic man.
(3) The significance of the differences in these two patterns of actin is discussed in terms of differences in the accommodative ability and static lens shape in these two animals.
(4) The epithelium of Brunner's gland stained intensely with Ricinus communis agglutinin-I (RCA-I), succinylated-WGA (S-WGA) and wheat-germ agglutinin (WGA), moderately with Bandeirea simplicifolia agglutinin-I (BS-I), Concanavalia ensiformis agglutinin (Con A) peanut agglutinin (PNA) and Ulex europaeus agglutinin-I (UEA-I) and occasionally with Dolichos biflorus agglutinin (DBA), Lens culinaris agglutinin (LCA) and soybean agglutinin (SBA).
(5) That is, he believes, to look at massively difficult, interlocking problems through too narrow a lens.
(6) The advantages of the incision through the pars plana ciliaris are (1) easier approach to the vitreous cavity, (2) preservation of the crystalline lens and an intact iris, and (3) circumvention of the corneal and chamber angle complications sometimes associated with the transcorneal approach.
(7) The third patient was using an extended-wear soft contact lens for correction of residual myopia.
(8) The cellularity depends on the type of the lens and the material of the lens and on the clinical picture of the disease.
(9) Although lens haemagglutinins were detected in 6 out of 7 rabbits, in only 3 of the 6 animals did the titre reach a maximum of 1:640.
(10) Dioptric aniseikonia was calculated between 1 month and 24 months after surgery (with Gruber's and Huber's computer program) on the basis of most recently obtained values (bulb axis length, depth of the anterior chamber, lens thickness, necessary refraction), and compared with subjective measurements taken with the phase difference haploscope.
(11) We propose that a channel with these properties could contribute to maintenance of lens transparency and fluid balance.
(12) Although the lens did not alter stereopsis, it did produce severe color discrimination losses for normal and dichromatic subjects.
(13) The general efficacy of this intraocular lens compared with other anterior chamber lenses was not addressed in this study.
(14) However, the monkey lens low molecular weight proteins differ from the human low molecular weight proteins in charge as well as molecular weight determined by SDS-PAGE.
(15) Fifty-five myopic naval personnel with no previous contact lens experience were put through a three-week study using these contact lenses.
(16) A Stryker turning frame was used during surgical removal of a posterior displaced lens.
(17) The biocompatibility and fixation of a new silicone intraocular lens was evaluated in the cat eye.
(18) Both organisms have previously been found to be sequestered in the posterior lens capsule by histological and microbiological examination of excised capsular specimens.
(19) Previous experiments had demonstrated that the receptors for the lectins soybean agglutinin (SBA), wheat germ agglutinin, concanavalin A and Lens culinaris agglutinin all were relatively uniformly distributed on both myoblasts and myotubes, and that SBA receptors were capable of rapid redistribution on myotubes but not myoblasts at 4 degrees C (Sawyer & Akeson, 1983).
(20) The relative permittivity and conductivity of rabbit eye lens were measured in the frequency domain between 2 and 18 GHz at temperatures of 37 and 20 degrees C. An analysis of the data suggested that a significant proportion of the bulk water in nuclear and cortical lens tissue may behave differently to pure water.