I am new to needing glasses, have had perfect vision my whole life until just before the 2016 season. I wear progressive lenses for indoor and night use and have prescription sun glasses for distance only outdoors. I have not been able to shoot with my prescription glasses, it seems extremely uncomfortable and awkward for me. It seems that when I focus my scope or binos that I am able to see crystal clear without glasses. I hear about people talking about eye relief for glasses, etc. Also people mention which eyecups are better for glasses, etc. My question is if I am really able to correct my vision with nothing but the focus of the optic? If this is the case, why do they make adjustable eyecups and relief for glasses wearers?