▁for ▁mapping ▁the ▁up - close ▁display ▁to ▁a ▁wide ▁field ▁of ▁view , ▁while ▁also ▁providing ▁a ▁more ▁comfortable ▁distant ▁point ▁of ▁focus . ▁One ▁challenge ▁with ▁this ▁is ▁providing ▁consist ency ▁of ▁focus : ▁because ▁eyes ▁are ▁free ▁to ▁turn ▁within ▁the ▁head set , ▁it ' s ▁important ▁to ▁avoid ▁having ▁to ▁ref ocus ▁to ▁prevent ▁eye ▁stra in . ▁ ▁F res nel ▁l enses ▁are ▁commonly ▁used ▁in ▁virtual ▁reality ▁head sets ▁due ▁to ▁their ▁compact ness ▁and ▁light weight ▁structure . ▁The ▁l enses ▁do ▁not ▁use ▁multiple ▁pieces ▁of ▁material ▁in ▁their ▁l enses ▁like ▁other ▁l enses , ▁but ▁the ▁l ens ▁will ▁be ▁broken ▁down ▁into ▁sections , ▁allowing ▁the ▁individual ▁to ▁have ▁a ▁wider ▁range ▁of ▁view . ▁The ▁issue ▁seen ▁with ▁the ▁l ens ▁consists ▁of ▁seeing ▁the ▁rid ges ▁of ▁the ▁l enses ▁when ▁the ▁head set ▁is ▁not ▁properly ▁aligned ▁on ▁the ▁head . ▁ ▁The ▁l enses ▁introduce ▁dist ort ion ▁and ▁chrom atic ▁aber r ation , ▁which ▁are ▁typically ▁corrected ▁in ▁software . ▁The ▁l enses ▁can ▁also ▁be ▁adjust ed ▁dynamically ▁to ▁account ▁for ▁a ▁user ' s ▁e y eg lass ▁pres cription ▁so ▁that ▁the ▁user ▁can ▁use ▁the ▁head set ▁without ▁correct ive ▁e y eg lass es . ▁ ▁Cont rollers ▁ ▁Virtual ▁reality ▁was ▁used ▁by ▁N intendo ' s ▁W ii ▁game ▁console ▁by ▁having ▁the ▁player ▁use ▁a ▁controller ▁to ▁interact ▁with ▁the ▁game ▁of ▁their ▁choice , ▁often