▁col lim ation ▁to ▁avoid ▁eye ▁stra in ▁and ▁fat igue . ▁ ▁Most ▁modern ▁bin oc ular s ▁are ▁also ▁adjust able ▁via ▁a ▁h ing ed ▁construction ▁that ▁enables ▁the ▁distance ▁between ▁the ▁two ▁teles cope ▁hal ves ▁to ▁be ▁adjust ed ▁to ▁accommod ate ▁view ers ▁with ▁different ▁eye ▁separation ▁or ▁" inter p up ill ary ▁distance ". ▁Most ▁are ▁optimized ▁for ▁the ▁inter p up ill ary ▁distance ▁( typ ically ▁ 5 6   mm ) ▁for ▁adult s . ▁ ▁Image ▁stability ▁▁ ▁Some ▁bin oc ular s ▁use ▁image - st abil ization ▁technology ▁to ▁reduce ▁sh ake ▁at ▁higher ▁magn ifications . ▁This ▁is ▁done ▁by ▁having ▁a ▁gy ros cope ▁move ▁part ▁of ▁the ▁instrument , ▁or ▁by ▁power ed ▁mechan isms ▁driven ▁by ▁gy ro scop ic ▁or ▁in ert ial ▁detect ors , ▁or ▁via ▁a ▁mount ▁designed ▁to ▁opp ose ▁and ▁d amp ▁the ▁effect ▁of ▁sh aking ▁movements . ▁St abil ization ▁may ▁be ▁enabled ▁or ▁disabled ▁by ▁the ▁user ▁as ▁required . ▁These ▁techniques ▁allow ▁bin oc ular s ▁up ▁to ▁ 2 0 × ▁to ▁be ▁hand - h eld , ▁and ▁much ▁improve ▁the ▁image ▁stability ▁of ▁lower - power ▁instruments . ▁There ▁are ▁some ▁dis adv antages : ▁the ▁image ▁may ▁not ▁be ▁quite ▁as ▁good ▁as ▁the ▁best ▁un st abil ized ▁bin oc ular s ▁when ▁tri pod - mount ed , ▁stabil ized ▁bin oc ular s ▁also ▁tend ▁to ▁be ▁more