How Do Bees See?

How do bees perceive the world?

Vision is essential to bees as they must hunt for flowers to find nectar and pollen. Because of this, they are well adapted to be able to seek the right plants. Bees can use odor cues to hone in on a flower, but that only works when they’re already pretty close. Vision is essential to help the bees find flowers at a distance.

  How Many Eyes?

It is often said that a bee has 5 eyes, 3 ocelli eyes and 2 compound eyes, but that is somewhat misleading,

  Ocelli

The 3 ocelli or 'simple eyes' poke up like glassy marbles from the top of the head, but amount to little more than light-sensitive nobs. The ocelli are simple eyes that bees use to orientate themselves towards the sun. Located in a triangular shape are 2 dorsal ocelli and 1 central ocelli.

The ocelli are incapable of forming images; they appear to play a more limited role in tracking patterns of light intensity and polarization. Bees use ocelli to navigate, particularly at dusk.

  Compound Eyes

The real action takes place inside the 2 enormous compound eyes that frame and dominate a bee's face. Each one contains over 6,000 facets that constantly beam their individual views of the world to the brain. The brain knits together all those pictures into a single, wide-angle composite image.

Because the eye is rigid, its focal distance if fixed and quite short. The makes anything seen from afar look like a highly pixilated blur. Flowers, nest holes, fellow bees and other objects only resolve into sharp focus up close - within a few inches.

The myopic view of the world may seem limiting, but bees compensate for this with an extraordinary ability to sense motion. Every compound eye facet is individually hard-wired, from lens to brain, so that anything moving through the bee's field of vision sets off a whole cascade of reactions.

Even the smallest motions stimulate hundreds of facets, all of which glimpse that moving object from a slightly different angle. The result is a hyper-awareness that allows bees to unconsciously calculate speed, distance and trajectory.

The compound eyes of male bees are much larger as their primary goal in life is to spot motion — the streak of an eligible female bee passing by on her nuptual flight.

Bees can’t see the color red, but they can see in the ultraviolet spectrum which is especially important to bees as it helps outline landing zones on flowers.

  Hairy Eyes

Honey bees have hairy eyes, although this is not true for all species of bees. The hairs may have clever function. The spacing between the hairs on a honey bees eyes is the same as a single grain of dandelion pollen – a highly common pollen collected by bees.

The honey bee is able to keep the pollen suspended above its eye, allowing for its legs to comb through the hairs and collect particles when the honey bee is grooming. Honey bees are able to carry a significant proportion of their own body weight in pollen due to these cleverly placed hairs.

  The Bee's Visual Spectrum

Humans see light in wavelengths from approximately 390 to 750 nanometers (nm). These wavelengths represent the spectrum of colors we can see. Bees, like many insects, see from approximately 300 to 650 nm. That means that bees can’t see the color red, but they can see in the ultraviolet spectrum (which humans cannot).

Ultraviolet vision is especially important to bees as these ultraviolet patterns often outline landing zones, pointing them towards the part of the plant containing nectar and pollen.

Bees can also easily distinguish between dark and light – making them very good at seeing edges. This helps them identify different shapes, though they can have trouble distinguishing between similar shapes that have smooth lines – such as circles and ovals.