INTERNATIONAL ORGANIZATION FOR STANDARDIZATIONWIEX~YHAPOCIHAF OW AHM3AYMH i !O CTAHL1APTM3A~MM ORGANISATION INTERNATIONALE DE NORMALISATION Optique et instruments d’optique Ophtalmologie iche/ie gradd[.]
INTERNATIONAL ORGANIZATION Optique et instruments iast edition FOR STANDARDIZATIONWIEX~YHAPOCIHAF d’optique - Ophtalmologie OW-AHM3AYMH i-!O CTAHL1APTM3A~MM.ORGANISATION INTERNATIONALE DE NORMALISATION - iche/ie gradde - escriptora : 0pticaSequipment, ophthahic sptics, measusing scales, specifications Price based on page rganimation BorStan rmaHycarriedsut throuyh IS srk of preparingBnternatisnal h a subject for which a technkal committee has been established has represented on that tormit nmentaf, Sniiaison wit the technica8 committees arc circulated to nal Standards by ir acceptance as hteana repare rs ShQUBd nste that all I that any r-ederence latest editicsn, unless Qt~g~~~sg stated y Technical Committee E ardsUnderg@ rovisionf chdther~~tg~~at~Q~a~Sta ecifications for the angulaa design of scales, reticles or in instruments fsr d correctiwe lenses for ccmrdinate System t other display means inco hg optical data on kuma @Y@S eseri the syste The coordinate System, specified in this International Standard and sometimes cafled the TA system, describes a) the angular orientatisn of the cylinder axis, when used to describe the refractive error of the eye or the redractive effect of a contact or spectacle lens; bj r orient The coordinate System is the Same whether it refers to the right eye or to the left eye When used, the coordinate System is as it appears Po a person wiewing the e spectacle lenses - correctly placed in front of the eyes - frsm outside The zero axis sf the caordinate System is horizontal and, in the case where the numbering is hm O” to 360°, it is the righthand portisn of tke horizontal axis The angular value increases in the counter-clockwise direction with XI0 corresponding to the vertical axis When used ts define cylinder axis or orientation of principal curvature meridians, the angular value shall be expressed as a number between Cl0 and 180° When used to define prism base orientation, the angular value shall pressed as a number between Q” and 360Q, marked by the Point where the base of the prism touches the TABO circle sf the prism base, des ismatic polar coordinates; aincipal curvature meric9 the angular orientation of t to describe the curvature 0% a surface such as the cornea or a lens ight eye An example od a sca3e design described in clause 2, is SR shown witk a specific angular sca meant ts imply that other designs cannot be used and still $38 considered as within the scope and intent of this ~~ter~ati~~a~ Standard