Major portions were filmed about the Queen Mary, which is based in Long Beach, CA as a tourist attraction.
Corky is held by the grease monkeys. They have raisin wine which has a certain effect on the eyesight. Methanol, wood alcohol, is famously toxic and is especially damaging to the retina. During Prohibition, backwoods moonshine had a deserved reputation for containing enough methanol to cause blindness (sometimes only temporary). Homebrew wine and beer very rarely contains noticeable levels of methanol, but some people still think poorly made beer or wine can cause blindness.