I flew a trial lesson for a blind gentleman with BDFA. I was staggered just how much he could detect via physiological sensations and peripheral cues, and he made commendable effort S & L. Very heart warming for both of us and I would jump at the opportunity to do it again. The smile on his face was most rewarding. Hardest part was leaving him with his guide dog on the unknown territory of the platform of the local railway station. A memorable student.