For other uses, see Zechariah. The male given name Zechariah is derived from the Hebrew ×Ö°×Ö·×¨Ö°×Ö¸×, meaning The Lord has remembered.. It has been translated into English in many variant forms and spellings, including Zachariah, Zacharias and Zachary. It was the name of various men in the Bible.
Double Refraction in Minerals Double refraction is the splitting of a single ray of light into two refracted rays when passing through an anisotropic mineral. All anisotropic minerals exhibit double refraction. Double refraction can be practically observed by placing a transparent Calcite (Iceland spar) crystal on a sheet of paper with a black dot on it. When the dot is viewed through the crystal, two dots are seen.
Refraction is the process of determining the glasses prescription to correct the near-sighted or far-sighted condition.See Optics for an explanation of the terms near-sighted, far-sighted, astigmatism and presbyopia.he main distance categories are shown above, with the colors matching the diagrammatic glasses shown next. 1  Reading and close work are usually done around 14 inches. 2  Think of intermediate as armâs length, usually 18 to 24 inches, where a lot of lifeâs activities occur. 3  The computer. 4  Room distance.