In art, the horizon line (sometimes called eye level) marks the point where the sky meets the land or sea below. The horizon line helps to arrange items in a painting or drawing in their right positions, and makes them appear genuine. Artists utilise the horizon line to make objects in paintings proportionate, and to set the stage for outdoor and landscape paintings.

Although painters commonly use the words “horizon line” and “eye level” synonymously, the horizon line normally refers to drawings or paintings done using an outdoor setting. Eye level, in contrast, depicts the distinction between the sky (or ceiling) and land (which could appear as items such as tables, desks and chairs as well) in paintings of indoor scenes. The horizon line and eye level serve to determine proportions accurately by appearing at the real height of viewers’ eyes when looking at a scene or items. For instance, if the far end of a table appears halfway up a vase in a painting, that line becomes the horizon line. Artists also employ horizon lines to construct reference points, and may use them to create focal points. Horizon lines appear as flat and horizontal lines across a page, and occur as parallel lines pertaining to linear perspective.