The function of immersion oil is to direct the light from the microscope directly to the slide and stop it from refracting. There are two characteristics that immersion oil contributes to for the image viewed through the microscope. They are finer resolution and brightness. Oil immersion objectives are generally available from 40 to 120x.For more information on oil immersion visit
. http://www.cargille.com/immersionoilmicroscope.shtml.
