| isocyclic compound | Any compound in which the constituent atoms, or any part of them, form a ring. Used mainly in organic chemistry where: 1) numerous compound's contain rings of carbon atoms (carbocyclic compound's) or carbon atoms plus one or more atoms of other types (heterocyclic compound's), usually nitrogen, oxygen, or sulfur; 2) where the atoms in the ring are all of the same element (homocyclic or isocyclic compound); 3) where the ring is saturated or contains nonconjugated double bonds (alicyclic compound), the compound is similar in properties to the corresponding acyclic compound (e.g., cyclohexane resembles hexane); 4) where the ring contains conjugated double bonds in a closed loop in which there are 4n + 2 (where n is an integer) delocalised π electrons (Huckel's rule) (aromatic compound; e.g., benzene, pyridine), it is more stable than the corresponding saturated ring and exhibits unusual chemical properties characteristic of itself and not of other types of rings or of acyclic compound's. These aromatic compounds have the ability to sustain an induced ring current. Synonym: closed chain compound, ring compound. (05 Mar 2000) |
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| open chain compound | An organic compound in which the chain does not form a ring. Synonym: aliphatic compound, open chain compound. (05 Mar 2000) |
| organic compound | <chemistry> A compound containing carbon. (11 Jan 1998) |
| lens, compound | <microscopy> A lens composed of two or more separate pieces of glass or other optical maternal. These component pieces or elements may or may not be cemented together. A common form of compound lens is a two-element objective, one element being a converging lens of crown glass and the other a diverging lens of flint glass. The combination of suitable glasses or other optical materials (plastics, minerals) properly ground and polished reduces aberrations normally present in a single lens. (05 Aug 1998) |
| accessory organs of the eye | The eyelids, with lashes and eyebrows, lacrimal apparatus, conjunctival sac, and extrinsic muscles of the eyeball. Synonym: organa oculi accessoria, accessory organs, accessory visual apparatus, adnexa oculi, appendages of eye. (05 Mar 2000) |
| accommodation of eye | The increase in thickness and convexity of the eye's lens in order to focus the image of an external object upon the retina. (05 Mar 2000) |
| amaurotic cat's eye | A yellow reflex from the pupil in cases of retinoblastoma or pseudoglioma. (05 Mar 2000) |
| anterior chamber of eye | The space between the cornea anteriorly and the iris/pupil posteriorly, filled with a watery fluid (aqueous humor) and communicating through the pupil with the posterior chamber. Synonym: camera anterior bulbi, camera oculi anterior, camera oculi major. (05 Mar 2000) |
| anterior eye segment | That part of the eyeball anterior to the lens. (12 Dec 1998) |
| antibiotic eye drops | <pharmacology> A medication that is pH balanced to allow placement into the eye for the purpose of killing bacteria. Examples include: Bleph-10, Chloromycetin, Cortisporin-Ophthalmic, Gantrisin, Genoptic, Gentacidin, Garamycin, Gantrisin, Ilotycin, Sodium Sulamyd and Sulphair. (27 Sep 1997) |
| aphakic eye | The eye from which the lens is absent. (05 Mar 2000) |
| appendages of eye | The eyelids, with lashes and eyebrows, lacrimal apparatus, conjunctival sac, and extrinsic muscles of the eyeball. Synonym: organa oculi accessoria, accessory organs, accessory visual apparatus, adnexa oculi, appendages of eye. (05 Mar 2000) |
| artificial eye | A curved disk of opaque glass or plastic, containing an imitation iris and pupil in the centre, inserted beneath the eyelids and supported by the orbital contents after evisceration or enucleation; it may be ready-made (stock) or custom-made. (05 Mar 2000) |
| bird's-eye | <botany> A plant with a small bright flower, as the Adonis or pheasant's eye, the mealy primrose (Primula farinosa), and species of Veronica, Geranium, etc. Source: Websters Dictionary (01 Mar 1998) |
| black eye | Ecchymosis of the lids and their surroundings. (05 Mar 2000) |