Link:   http://www.beeculture.com/bees-see-matters/

Excerpt:

Scientists consider bees to be a keystone species. They are so important to an ecosystem that it will collapse without them. At least 90 commercially grown crops depend upon bee pollination for survival. How important is the pollination by bees? Ask an almond grower. Without bees, there would be no almonds. Apples, blueberries, cherries, avocados, cucumbers, onions, grapefruit, oranges and pumpkins would also disappear. Bees are the undisputed champions of the pollination world. And their secret weapon? Sight.

 

The remarkable eyesight of bees has long been a source of fascination in the scientific community. A hundred years ago, Nobel Prize-winning scientist Karl von Frisch proved that bees can see color. The color we see is based upon how a pigment absorbs and reflects light. When light hits an object, some is absorbed and some is reflected. Our eyes perceive the reflected portion as color. The brilliant color in flowers is a way of attracting pollinators, such as bees. The colors of flowers help target the areas of nectar. That’s the reason why petals are usually a different color than leaves. Even though humans can see more colors, bees have a much broader range of color vision. Their ability to see ultraviolet light gives them an advantage when seeking nectar. Many patterns on flowers are invisible to humans. These nectar “bulls-eyes” are visible only to animals, such as bees, that have the ability to see ultra-violet light. This “bee vision” makes finding nectar much easier. In fact, some flowers such as sunflowers, primroses and pansies have nectar guides that can only be seen in ultra-violet light.

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Bees have two different types of eyes-each with separate functions. The three smaller eyes in the center-top of a bee’s head are called ocelli. Ocelli comes from the Latin word “ocellus” which means little eye. These little bee eyes have single lenses and help the bee maintain stability and navigate. They enable the bee to judge light intensity and stay oriented. Using these ocelli, bees can gather light and see ultra-violet light, helping them to detect UV flower colors.