▁For ▁comfort , ▁ease ▁of ▁use , ▁and ▁flex ibility ▁in ▁applications , ▁larger ▁bin oc ular s ▁with ▁larger ▁exit ▁pup ils ▁are ▁satisf actory ▁choices ▁even ▁if ▁their ▁cap ability ▁is ▁not ▁fully ▁used ▁by ▁day . ▁ ▁E ye ▁relief ▁E ye ▁relief ▁is ▁the ▁distance ▁from ▁the ▁rear ▁e y ep ie ce ▁l ens ▁to ▁the ▁exit ▁pup il ▁or ▁eye ▁point . ▁It ▁is ▁the ▁distance ▁the ▁observer ▁must ▁position ▁his ▁or ▁her ▁eye ▁behind ▁the ▁e y ep ie ce ▁in ▁order ▁to ▁see ▁an ▁un v ign ett ed ▁image . ▁The ▁longer ▁the ▁foc al ▁length ▁of ▁the ▁e y ep ie ce , ▁the ▁greater ▁the ▁potential ▁eye ▁relief . ▁Bin oc ular s ▁may ▁have ▁eye ▁relief ▁r anging ▁from ▁a ▁few ▁mill im eters ▁to ▁ 2 . 5 ▁cent im eters ▁or ▁more . ▁E ye ▁relief ▁can ▁be ▁particularly ▁important ▁for ▁e y eg lass ▁wear ers . ▁The ▁eye ▁of ▁an ▁e y eg lass ▁wear er ▁is ▁typically ▁further ▁from ▁the ▁eye ▁piece ▁which ▁necess it ates ▁a ▁longer ▁eye ▁relief ▁in ▁order ▁to ▁avoid ▁v ign et ting ▁and , ▁in ▁the ▁extreme ▁cases , ▁to ▁con serve ▁the ▁entire ▁field ▁of ▁view . ▁Bin oc ular s ▁with ▁short ▁eye ▁relief ▁can ▁also ▁be ▁hard ▁to ▁use ▁in ▁instances ▁where ▁it ▁is ▁difficult ▁to ▁hold ▁them ▁steady . ▁ ▁Close ▁focus ▁distance ▁Close ▁focus ▁distance ▁is ▁the ▁closest ▁point ▁that ▁the ▁bin oc ular ▁can