Bit, well way off topic, co-worker and I were ribbing each other about how easy the "other" branch has it, he made the comment that he was home bound after a tour on the sub because his depth perception was distorted and couldn't drive for a few days after getting on dry land. In boat everything is about 40 feet or less and this screws with depth perception, true or B.S.
Before the sub, perfect vision.
bout 2.5 years later(into a 3.5 tour) glasses for distance. But thats a 1 person data point.
And yes, you're never far from a bulkhead.