Why local people draw eye icons on boats in Vietnam? - Eye painting for the boat is a custom derived from spontaneous, legendary notions did local people communicate with eachother. Not only Viet Nam but many other parts of the world have the same culture, although not the same completely, but for the same purpose of eye painting.
As well as having fish, they are like fish, so it also needs to have eyes to guide them to look at them. Indeed, deep to see where there are many shrimp.