Swiss cheese is a generic name in North America for several related varieties of cheese. mainly of North American manufacture, which resemble Emmental Cheese, a yellow, medium-hard cheese that originated in the area around Emmental, in Switzerland. Some types of Swiss cheese have a distinctive appearance, as the blocks of the cheese are riddled with holes known as "eyes". Swiss cheese without eyes is known as "blind"
In general, the larger the eyes in a Swiss cheese, the more pronounced its flavor because a longer fermention period gives the bacteria more time to act. This poses a problem, however, because cheese with large eyes does not slice well and comes apart in mechanical slicers. As a result, industry regulators have limited the eye size by which Swiss cheese receives the Grade A stamp