The optics system of this binocular makesuse of a BaK4 porro prism with ahigh refractive index, in addition all of the prism and lenses surfaces are multi coated to greatly reduce light loss achieving asharp and clear field of visioneven in the edge. Besides,the long eye relief design of the eyepieces lenses and the use of twist up type eyecupsmakes the use of this binoculars easy and comfortable even for people wearing glasses.