What's the difference between optical and refraction?

Optical


Definition:

  • (a.) Of or pertaining to vision or sight.
  • (a.) Of or pertaining to the eye; ocular; as, the optic nerves (the first pair of cranial nerves) which are distributed to the retina. See Illust. of Brain, and Eye.
  • (a.) Relating to the science of optics; as, optical works.

Example Sentences:

  • (1) Following central retinal artery ligation, infarction of the retinal ganglion cells was reflected by a 97 per cent reduction in the radioactively labeled protein within the optic nerve.
  • (2) This study examined both the effect of variations in optical fiber tip and in light wavelength on laser-induced hyperthermia in rat brain.
  • (3) The number of axons displaying peptide-like immunoreactivity within the optic nerve, retinal or cerebral to the crush, and within the optic chiasm gradually decreased after 2-3 months.
  • (4) Once the normal variations are mastered, appreciation of retinal, choroidal, optic nerve, and vitreal abnormalities is possible.
  • (5) Chromatolysis and swelling of the cell bodies of cut axons are more prolonged than after optic nerve section and resolve in more central regions of retina first.
  • (6) CW Nd:YAG light transmitted by fiber optic cable and sapphire crystal was applied transsclerally to the ciliary body of pigmented and albino rabbits.
  • (7) Unlike results seen in the goldfish optic nerve, injury to the rat optic nerve induced no observable increase in laminin content or change in its distribution.
  • (8) This is the first report of anterior ischemic optic neuropathy as a result of hemodialysis-associated hypotension.
  • (9) It is shown that, by comparison of a reacting mixture at chemical equilibrium with a non-reacting but equally composed one, the sum of the mean concentrations of the reaction products can immediately be taken from optical absorption or from interferometric measurements.
  • (10) A television camera scans the spread through microscope optics; computer and special purpose electronics process the video signals to generate run length histograms.
  • (11) The purity and configuration of each isomer of the free acid and N-chloroacetylated derivative were ascertained by: (a) paper chromatography in five solvent systems, (b) elemental analysis, (c) Van Slyke nitrous acid determination of alpha-carbonyl carbon, and (d) Van Slyke ninhydrin determination of alpha-carbonyl carbon, and (e) optical rotation.
  • (12) The optical and oxygen binding properties of the reconstituted myoglobins containing two isomeric monoformyl-monovinylhemins were found to be different.
  • (13) These images were previously determined by using a recently developed hybrid optical-digital method.
  • (14) The development of optical fibers capable of transmitting laser energy has encouraged the experimental use of laser irradiation for the treatment of acquired cardiovascular disorders.
  • (15) This technique is sensitive to the optical anisotropy within the muscle, including that due to intrinsic properties of the protein molecules as well as that due to the regular arrangement of proteins in the surrounding medium.
  • (16) Patients should be evaluated by perimetry using an appropriate strategy and contrast sensitivity testing, along with careful examination of the optic discs.
  • (17) Thus, during treatment with ethambutol visually (pattern) evoked potentials may reveal a surprisingly high percentage of subclinical optic neuritis.
  • (18) The optical efficiencies are similar and depend on the match of the excitation characteristics of the stain with the emission spectra of the light source.
  • (19) Morphological results demonstrated that 30 Gy irradiated animals showed extensive necrosis primarily in the fimbria, which extended into the internal capsule, optic nerve, hippocampus, and thalamus.
  • (20) A compact attachment for microscope-type instruments is described enabling to introduce, rapidly and qualitatively, minute biological speciments into melted embedding medium and ensuring the safety of optics.

Refraction


Definition:

  • (n.) The act of refracting, or the state of being refracted.
  • (n.) The change in the direction of ray of light, heat, or the like, when it enters obliquely a medium of a different density from that through which it has previously moved.
  • (n.) The change in the direction of a ray of light, and, consequently, in the apparent position of a heavenly body from which it emanates, arising from its passage through the earth's atmosphere; -- hence distinguished as atmospheric refraction, or astronomical refraction.
  • (n.) The correction which is to be deducted from the apparent altitude of a heavenly body on account of atmospheric refraction, in order to obtain the true altitude.

Example Sentences:

  • (1) In the group of high myopia (over 20 D), the mean correction was 13.4 D. In the group with refraction between 0 and 6 D, 88% of the eyes treated had attained a correction between -1 and +1 D 3 months postoperatively.
  • (2) The molar refractivity has been shown to be a superior parameter for the description of the activity of sulphonamides than the sum of electronegativities of atoms making up a heterocyclic substituent in the sulphonamide molecule and molecular weight of the substituent.
  • (3) A new approach is presented to the refractive procedure by adding observation, both surreptitious and direct, as an adjunct, an aid and a supplement to differential diagnosis in a refractive examination and in visual analysis.
  • (4) 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.
  • (5) These versions offer different advantages and are selected according to the particular field of application and the refraction of the surgeon.
  • (6) The refraction of his mild hyperopic eyes (+0,5 dpt) changed to -5,5 dpt and the intraocular pressure increased to 40 mm Hg in the right and 42 mm Hg in the left eye.
  • (7) These observations suggest that refractive anomalies such as anisometropia that limit high frequency spatial resolution and binocular integration can present a major obstacle to the postnatal development of binocular vision.
  • (8) A retrospective study was performed to evaluate the effect of recipient-donor trephine disparity on refractive error and corneal curvature post-suture removal in keratoconus.
  • (9) Scientists and clinicians concerned with underwater vision have not considered the relationship between chromatic aberration, water color, and the refractive state of the eye.
  • (10) As the refractive status changes a curve is traced out on the graph.
  • (11) The change in refractive astigmatism was as high as 1.50DC (diopter cylinder).
  • (12) There is a problem in this approach if the angle between the direction of tracked beam and the direction of tracking translation is not zero due to refraction or other effects.
  • (13) We find good agreement between the model calculations and the experimental results indicating that edge birefringence can be attributed to the change in polarization of light that is refracted and reflected by dielectric interfaces.
  • (14) The corneal sensibility was examined with the aesthesiometer of Draeger in 41 patients after refractive corneal surgery, 31 patients after radial keratotomy, 5 after epikeratophakia, 5 after excimer laser ablation.
  • (15) Extraordinarily wide angles were observed in all cases and myopia was a common refractive error.
  • (16) There was no connection between the cholesterol level, refraction or visual acuity.
  • (17) The refractive changes in 84 children (155 eyes) following horizontal strabismus surgery and in 97 children (181 eyes) without surgical intervention were studied.
  • (18) Refractive error and the ocular refractive components have heritabilities intermediate between zero and one, as complied from several studies, indicating familial resemblance, but also non-genetic variation.
  • (19) Approximately 75% of repeat autorefractor measurements were within 0.50 D of the initial readings, and about 75% of measurements were within 1.00 D of the manual refractions.
  • (20) The refractive index profile in the equatorial plane of bovine lenses from over a wide age range is presented.