| EACD | eczematous allergic contact dermatitis |
|---|---|
| ECH | educator contact hour |
| FCH | faculty contact hour; family case home; fetal cystic hygroma |
| HAPC | high-amplitude peristaltic contraction; hospital-acquired penetration contact |
| ICDRC | International Contact Dermatitis Research Center |
| plan apochromatic objective lens | <physics> A modern, high-numerical aperture microscope objective lens designed with high degrees of corrections for various aberrations. It is corrected for spherical aberration in four wavelengths (dark blue, blue, green, and red), for chromatic aberration in more than these four wavelengths, and for flatness of field. A single Plan Apo objective may contain as many as 11 lens elements. (05 Aug 1998) |
|---|---|
| compound lens | An optical system of two or more lenses. (05 Mar 2000) |
| concave lens | A diverging minus power lens. Synonym: minus lens. (05 Mar 2000) |
| concavoconcave lens | A lens that is concave on two opposing surfaces. Synonym: concavoconcave lens, double concave lens. (05 Mar 2000) |
| concavoconvex lens | A converging meniscus lens that is concave on one surface and convex on the opposite surface. (05 Mar 2000) |
| condenser or condenser lens | <physics> A term applied to lenses or mirrors designed to collect, control, and concentrate radiation in an illumination system. (05 Aug 1998) |
| multifocal lens | A lens with segments providing two or more powers; commonly, a trifocal lens. (05 Mar 2000) |
| plus lens | A converging lens. Synonym: plus lens. (05 Mar 2000) |
| convex lens | A converging lens. Synonym: plus lens. (05 Mar 2000) |
| convexoconcave lens | A minus power lens having one surface convex and the opposite surface concave, with the latter having the greater curvature. (05 Mar 2000) |
| convexoconvex lens | A lens with both surfaces convex. Synonym: convexoconvex lens, double convex lens. (05 Mar 2000) |
| corneal lens | Contact lens of plastic without scleral portions. (05 Mar 2000) |
| cortex of lens | The softer, more superficial part of the lens of the eye that encloses the central part or nucleus; its refractive power is less than that of the nucleus. Synonym: cortex lentis. (05 Mar 2000) |
| positive lens | <physics> Any lens with a positive focal length. Such lenses are thicker in the centre than around the circumference. There are three types of positive lenses, double convex or biconvex, planoconvex, converging concavoconvex or converging meniscus. (05 Aug 1998) |
| posterior pole of lens | The central point on the posterior surface of the lens. Synonym: polus posterior lentis. (05 Mar 2000) |