I have a problem getting a sharp in focus view of both the forsight element and the bull at the same time. now i need to use glasses for close up reading and at 10m distance my bi foc glassses are only slightly corrected. so either i go for shooting glasses or get an adjustable gehmann iris which has a fac for adjusting the optical correction. have you had this problem and overcome it. and if so can you offer advice here to assist me, thanks. Terry.