SENSORY SYSTEM, FUNCTION, ASSESSMENT, AND THERAPEUTIC MEASURES VISON & HEARING

Accommodation - ability of pupil to respond to near and far distances pt told to focus on far away object [size & shape observed] as examiner continues observing pupil -object held exactly 5 inches form pts face -normally pts eyes turn inward and pupils constrict ***ALSO KNOWN AS CONVERGENCE AND CONSTRICTION**** Accommodation - when eye shifts focus on object that is near pupil will constrict to force photons thru thickness of lens Accommodation and pupil constriction - increase number of photons that strike fovea centralis Accommodation of lens [divergent light rays] - come from nearby objection require more refraction -to help focus light rays ciliary muscle surround the lens contacts which narrows lens causing bulge into convex shape and thickens giving it more focus power Accommodation of the lens [paralellel rays] - the almost parallel light rays from distant objects require little refraction so the ciliary muscle encircling lens relaxes and lens flattens and thins