I have often wondered how the location and type of display (i.e. digital vrs. analog) effects the brain processing time. I have a digital speedometer and tach on the dash near the left heater vent .It looks out of place but I donít care because it works so well. To look down on gauges means the eyes have to focus (short) and then refocus up (long). As a person gets older this refocus takes longer and longer . Also information from analog gauges has to be processed differently then digital. Any budding scientist out there with an interest in cars? It would be an interesting study to see how location , type and perhaps color effects response times.
In regard to looking left and right. It has been shown that eyes move in different directions depending on what the brain is thinking and is unique to that person . So some people may find it easier to process numbers looking in one direction versus the other.