| macular coloboma | A defect of the central retina as a result of arrested development or intrauterine retinal inflammation. (05 Mar 2000) |
|---|---|
| coloboma | Congenital anomaly in which some of the structures of the eye are absent due to incomplete fusion of the foetal intraocular fissure during gestation. (12 Dec 1998) |
| coloboma iridis | Retention of the choroid fissure causing a congenital cleft of the iris, often associated with coloboma of the choroid, viable in the inferior ocular fundus, obsolete term for the iris defect resulting from a large surgical iridectomy. (05 Mar 2000) |
| coloboma lentis | A segment of the lens equator devoid of zonular fibres, giving the appearance of a notch. (05 Mar 2000) |
| coloboma lobuli | Congenital fissure of the lobule of the ear. (05 Mar 2000) |
| coloboma of choroid | A congenital defect of the choroid and retinal pigment epithelium exposing the sclera; the defect is usually situated below the optic disk in the region of foetal fissure. (05 Mar 2000) |
| coloboma of optic nerve | <anatomy, nerve> A congenital notch in the formation of the optic nerve, appearing as a craterlike excavation at the optic disk. (05 Mar 2000) |
| coloboma of vitreous | A congenital indentation of the vitreous body by mesoderm; associated with severe myopia. (05 Mar 2000) |
| coloboma palpebrale | A congenital notch in the eyelid margin. (05 Mar 2000) |
| Fuchs' coloboma | A congenital inferior crescent on the choroid at the edge of the optic disk; not associated with myopia. Synonym: congenital conus. (05 Mar 2000) |
| achromatic lens | A compound lens made of two or more lens's having different indices of refraction, so correlated as to minimise chromatic aberration. (05 Mar 2000) |
| acoustic lens | In ultrasonography, a lens used to focus or diverge a sound beam; may be simulated by electronic manipulation of signals. (05 Mar 2000) |
| anterior pole of lens | The central point on the anterior surface of the lens of the eye. Synonym: polus anterior lentis. (05 Mar 2000) |
| anterior surface of lens | The anterior surface of the lens of the eye. Synonym: facies anterior lentis. (05 Mar 2000) |
| aplanatic lens | A lens designed to correct spherical aberration and coma (q.v.). Synonym: periscopic meniscus. (05 Mar 2000) |