#38 - Law of Hydrostatic Emission
Eyes tend to be rather large in Anime. This is because they contain several gallons of water, which may be instantaneously released at high pressure through large tear ducts. The actual volume of water contained in the eyes is unknown, as there is no evidence to suggest that these reservoirs are actually capable of running out. The reason water tends to collect in the eyes is because Anime characters only have one large sweat gland, which is located at the back of the head. When extremely stressed, embarrassed, or worried, this sweat gland exudes a single but very large drop of sebaceous fluid.