Stupidity: When Doss buried the wounded soldier, leaving one eye out made no sense. It did nothing to help him. All it did was make it easier for the Japanese to spot him. It would've made sense to leave his nose and/or mouth out, so he could breathe. He did not need to see.
Suggested correction: A person who is unable to see is more likely to panic. When Doss buried the wounded Marine, he asked him to take a deep breath and trust him. By leaving one eye open, it allowed him to see the gravity of the situation as IJA soldiers walked by and maintain eye contact with Doss who hid under a dead Marine. After the suspicious IJA soldier bayoneted the body over Doss, he looked directly at where the wounded man was buried and kept walking. It was a crude method, but it likely saved them both.