| contact lens | A lens that fits over the cornea and sclera or cornea only; used to correct refractive errors. (05 Mar 2000) |
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| contact lens solutions | Sterile solutions used to clean and disinfect contact lenses. (12 Dec 1998) |
| refractive | Serving or having power to refract, or turn from a direct course; pertaining to refraction; as, refractive surfaces; refractive powers. Refractive index. <medicine> The ratio of the sine of the angle of incidence to the sine of the angle of refraction for a ray passing out of one of the media into the other. Origin: Cf. F. Refractif. See Refract. Source: Websters Dictionary (01 Mar 1998) |
| refractive accommodative esotropia | That type of esotropia eliminated by correction of hypermetropic refractive error. (05 Mar 2000) |
| refractive amblyopia | A suppression of central vision due to an unequal refractive error (anisometropia) of at least two diopters. This induces a sufficient difference in image size (aniseikonia) that the two images cannot be fused. In order to avoid confusion, the blurrier image is suppressed. Synonym: refractive amblyopia. (05 Mar 2000) |
| refractive errors | Deviations from the average or standard indices of refraction of the eye through its dioptric or refractive apparatus. (12 Dec 1998) |
| refractive index | <microscopy> The ratio of the velocity of light in a vacuum to the velocity in some medium. Refractive index generally increases with the atomic number of the constituent atoms. (05 Aug 1998) |
| refractive keratoplasty | Any procedure in which the shape of the cornea is modified, with the intent of changing the refractive error of the eye; for example, if the cornea is flattened, the eye becomes less myopic. See: photorefractive keratectomy, keratophakia, lamellar keratoplasty, thermokeratoplasty, keratomileusis, radial keratotomy. Synonym: keratorefractive surgery. (05 Mar 2000) |
| refractive keratotomy | Modification of corneal curvature by means of corneal incisions to minimise hyperopia, myopia, or astigmatism.In this type of radial keratotomy surgery, performed by excimer laser, pie-shaped pieces of cornea are removed under local anaesthetic. The resulting scar tissue formation reshapes the cornea. This class of surgery is somewhat unpredictable, and its long-term effects are still unknown. (05 Mar 2000) |
| allergic contact dermatitis | A delayed type IV allergic reaction of the skin with varying degrees of erythema, oedema, and vesiculation resulting from cutaneous contact with a specific allergen. Synonym: contact allergy. (05 Mar 2000) |
| balancing contact | The contact's between upper and lower dentures on the balancing or mediotrusive side for the purpose of stabilizing the dentures, the contact's between upper and lower dentures at the opposite side from the working or laterotrusive side (anteroposteriorly or laterally) for the purpose of stabilizing the dentures, the contact's between upper and lower natural or artificial teeth at the opposite side from the working or laterotrusive side. Synonym: balancing occlusal surface. (05 Mar 2000) |
| centric contact | The relation of opposing occlusal surfaces which provides the maximum planned contact and/or intercuspation, the occlusion of the teeth when the mandible is in centric relation to the maxillae. Synonym: centric contact. (05 Mar 2000) |
| microradiography, contact | <microscopy> A method of making micrographs by means of X-rays. The specimen is placed close to a fine-grained photographic emulsion at some distance from the X-ray source. The X rays pass through the specimen and the differential absorption and the scattering of the radiation is recorded by the emulsion. The resulting negative is examined and photographed through a light microscope. (05 Aug 1998) |
| close contact infection | <epidemiology> An infection which requires close contact, other than sexual contact, between susceptible and infectious individuals, for transmission. (05 Dec 1998) |
| contact | A mutual touching of two bodies or persons. Origin: L. Contactus = a touching together (18 Nov 1997) |