|
(3) Distortions of sight on vertical direction We observe lines with the same length described horizontally and vertically to have different lengths. This is because our eyes are placed in a horizontal line. Therefore, recognition of the length of a diagram in the horizontal direction is very accurate. But the diagram recognition of the vertical direction is not so sensitive. Therefore, the muscles of the optic nerves and the eyes must be more strained. It is explained in psychology that we see things exist in a further distance as the muscles are more strained. As a result, the length of the vertical direction of a diagram is recognized to be larger than the actual length. The following experiment may be one of the most concise examples, although there are various other methods to verify it. When students are asked to draw a perpendicular and
a horizontal line with the same length using a ruler without ticks, most
of them tend to draw the perpendicular line longer than the horizontal
line. It is concluded that human beings generally have a character to feel
the length of a vertical line longer the length of a horizontal line. Moreover,
when we are asked to mark the center of a vertical line, we tend to mark
a little above the actual center. Therefore, the lines in the center of
the letters E, F, and H are placed a little above the mid-point of the
vertical lines. The letters S and B of Helvetica and Universe are compared
in the Figure 321. When these letter are seen in the reverse direction,
the meaning of the figure caption is well understood.
|
