A study by Ankrum, Hansen, and Nemeth (1995) shows that the angle at which the monitor is tilted plays a role in discomfort. When we read a magazine, we naturally hold it so that the top is farther from the eyes than the bottom. This conforms to the way our visual system has developed since infancy. Almost anywhere we look, what is below the object we are looking at is closer to our eyes than what is above the object we are looking at. Our visual system has developed different abilities based on the environment it developed in.
The study found that neck, upper back and visual discomfort increased when the monitor was tilted so that the top was closer to the eyes than the bottom. Nova allows a monitor tilt that conforms to the way your visual system works.