Rainbow Formation:Eye

The perception of a rainbow depends on the observer's eyes lying in line with the different hues the white light of the Sun is turned into by raindrops. The higher these raindrops are in a rainbow, the redder they look to the observer; and the lower, the bluer.
Imagine a human eye in the lower left corner of the above illustration and try to answer the following questions.[br][br]When can a raindrop be seen?[br]When can a raindrop not be seen?[br]What colour will a raindrop look like to the observer when it is risen or lowered above the ground (by, for example, dragging it up and down)?[br]Why are secondary rainbows always higher than primary rainbows?[br]Why are secondary rainbows always dimmer than primary rainbows?

Information: Rainbow Formation:Eye