Bausch and Lomb astronomical telescopes are engineered and assembled to the same exacting standards applied to Bausch and Lomb binoculars and spotting scopes. It has long been accepted that the refracting telescope is capable of yielding perhaps the finest optical viewing performance of any telescope design.Light passes through the lens elements uninpeeded, until its bent only once at the star diagonal.As opposed to the reflector or cassegrain design, where light is reflected from mirrors and or lenses.