of course it depend also your eye's!
I have three pre war scope's on rifle's and all have a different optimal eye relief. I can only estimate it but think the Oigee Luxor 4x have 4 cm, the Zeiss Ziel 4 have 5cm and the Ajack 4x have 5,5cm.
A post war Pecar 4x81 have 7cm and this is the common distance for modern scope's iirc.
I dont feel that the Oigee is to close to my eye, its not a super magnum.