Effects of blue and black ink maker of different color paper on distance vision

  Objective   To study the discrepancies between blue and black ink on 18 kinds of color paper on distance vision(DV).

  Methods   30 fourth-grade pupils were selected.Blue or black targets were printed on each paper respectively in order to determine DV on right eye.

  Results   Compared with black ink, blue one depressed DV generally.The differences between them on DV were arranged in the order from the higher to the lower as follows: dark green(t=41.829, P=0.000), dark yellow, the Colored Rice Paper(CP), dark cyan, light red-mauve, middle orange-red, middle green, middle green-yellow, thin yellow, light yellow, light red-orange, light cyan(t=2.192), the White Paper(WP)(t=1.651), dark mauve-red, light orange-red, middle mauve-red, middle orange, dark yellow-orange.Among them, the former of WP had significant difference, and the latter of WP and WP had no significant difference.

  Conclusion   The DV of green and yellow paper which emit more medium wavelength light are depressed obviously by blue ink, especially high-saturation(dark color)paper.As the paper which emit more long or short wavelength light, there are usually no significant difference between blue and black ink on DV.