A bee’s vision is a powerful tool that helps find food sources and sense danger. Bees have a broad range of colour vision and can see ultraviolet light, which helps them identify nectar on flowers. Between their five types of eyes, bees can see the depth and three dimensions, maintain flight stability, judge light intensity, and keep their orientation.
How Do We Know How Bees Can See?
Some scientists use a bee’s sight capabilities to develop lenses for drones and other cameras. One of those abilities is 280-degree sight.
Researchers used acrylic glass and a curved mirror to create a 280-degree field of vision. Using 23-millimetre cameras, the drone aircraft can “see” a wider field and mimic the bee’s complex vision.
Additionally, behavioural experimentation is used to see which colours bees react to. This allows scientists to determine what wavelengths bees can see.
How Do Bees See?
Bees have five eyes: two compound eyes and three ocelli. Compound eyes can recognize colours and shades, while the ocelli process light wavelengths.
Compound eyes are made up of thousands of lenses, or facets, that allows bees to see colour and interpret images. Ocelli have single lenses that help the bee navigate in flight, stay oriented, and perceive light intensity.
What Are Facets?
Facets are the lenses of a bee’s compound eyes. Bees have thousands of these visual receptors in each eye. Facets allow bees to see colour and have 280-degree vision.
Looking through a bee’s eye is like looking through thousands of tiny holes, which interpret an image.
What Are Facets Connected To?
Facets have cones beneath them that are made up of visual and pigment cells. The facet and cones are connected to tubes called ommatidia, which make up a compound eye.
The ommatidia are composed of photoreceptor cells that allow bees to perceive certain colours. Light and colours pass through the various parts of a compound eye to send messages to bees’ brains to interpret images.
|Facets||Individual lenses in the shape of hexagons. This is what creates a bee’s mosaic-like vision.|
|Crystalline cone||Cones beneath facets that direct waves further into the compound eye.|
|Photoreceptors||Cells that create electrical signals from light. One ommatidium (one facet tube) has nine main photoreceptor cells.|
|Rhabdom||A receptive cylinder structure within an ommatidium.|
|Baseline membrane||Membrane that separates the ommatidium from its connecting optic nerve.|
|Photoreceptor axons||Cell axons of an optic nerve.|
These minuscule parts of a bee’s compound eye are complemented by a set of light-receptive eyes, known as ocelli.
What Are Ocelli?
Ocelli are three small eyes that bees use to detect light. These “simple eyes” have only one lens and do not form images like compound eyes, but see polarized patterns.
Do Bees See All Colours?
Bees do not see all colours, but they can see a broad range of the visible light spectrum. They base their sight on ultraviolet light, blue, and green. These colours are what the photoreceptor cells in their facet tubes receive.
Not every photoreceptor cell can see all three colours. There are specific cells in ommatidia that can translate individual colours, which come together to form an image.
Bees can see much of the same colour spectrum that humans do, while other creatures, like dogs, see a limited spectrum. While bees cannot see red because they do not have photoreceptors that perceive this colour, humans cannot see the kind of ultraviolet light that bees can.
Are Bees Near-Sighted?
Bees are most likely near-sighted, which means they can only see things close up. This near-sightedness is different from the way we interpret near-sightedness as humans, however. Bees, like other insects with compound eyes, lack focusing ability. The definition of an object becomes worse with distance.
Bees cannot see as far as humans can, but they have a wider field of vision. Humans only have 180 degrees of vision, while bees have 280 degrees.
Bees can also process images five times faster than humans can and they can perceive distances at a faster rate. Bees can see individual petals as they fly by or towards flowers. However, they see white light at a quicker speed than they do colour.
Can Bees See in the Dark?
Certain bee species are nocturnal and can see in the dark. Other bee species may be able to see in the low light around dusk and dawn. Most bee species don’t go out at night, however, since they are not able to see as well in the dark.
Nocturnal bees have larger ocelli than diurnal bees. Bees with larger-than-normal ocelli have a higher sensitivity to light, which allows them to fly in the dim moonlight.
Are Bees Trichromatic?
Bees are trichromatic like humans, which means that they have photoreceptors that can perceive three main colours and the colours between them.
Human trichromatic vision is based on red, blue, and green. Bees’ three colours are ultraviolet light, blue, and green.
Bees can’t see red, but they can see reddish wavelengths like yellow and orange. A combination of lighter wavelengths, along with ultraviolet light, allows them to see purple. Bees are most attracted to violet, purple, and blue.
Bees can see colours five times faster than humans can. They use this ability to spot flowers for pollination. Fast vision takes up a lot of energy, however, and is usually reserved for processing moving images.
Colours don’t change quickly, suggesting that bees’ fast colour processing is vital to their survival.
Bee Vision Range vs. Human Vision Range
Here are a few things that differentiate the vision of bees against that of humans:
- Colour spectrum: Bees can see 600 to 300 nanometers while humans’ range of vision is 700 to 400 nanometers. Bees’ spectrum includes ultraviolet light.
- Speed: Bees can process colour and images five times as fast as humans.
- Distance: Bees cannot see as far as humans can, but bees can see things that are close up in greater detail.
Humans cannot see the ultraviolet range of light. The human retina only responds to wavelengths that exclude infrared and ultraviolet. Ultraviolet has a shorter wavelength than violet, which ends at 380 nanometers.
The ultraviolet wavelength range is 100 to 400 nanometers. This is included in a bee’s visibility spectrum. However, some humans can see ultraviolet colours in rare cases, such as following a lens or cataract surgery.
There is also an eye condition called Aphakia, that causes people to see ultraviolet light as a side effect. Under normal conditions, our lenses block ultraviolet wavelengths. Aphakia is the absence of lenses, so ultraviolet light is no longer blocked.
How Do Bees See Light?
Bees can perceive light through their compound eyes and their ocelli. These three simple eyes are sensitive to light, but not colours. Ocelli do not see as well as compound eyes but act more like light detectors.
Bees use their ocelli to interpret the light from the sun or moon to navigate.
How Do Bees Detect Movements?
Bees may be better at detecting movement than humans. Bees have 4,000 to 7,000 facets in their compound eyes that allow them to sense all kinds of movement around them. They can perceive movements separated by 1/300th of a second.
Humans can detect movement separated by 1/50th of a second.
How Do Honey Bees Navigate at Day Time and at Night Time?
Honey bees use light from the sun or moon to navigate, which is interpreted by the ocelli.
Bees are also sensitive to elements that humans cannot detect easily, such as electromagnetic fields. Honey bees will use these senses to find food sources, which emit certain electromagnetic energy.
Pheromones are another way bees navigate. This chemical way of communication helps them recognize their hive mates, perceive threats, and find food.
Honeybees are diurnal and rarely go out at night.
What Is Polarized Light?
Polarized light is light that is shed in one direction at one angle. This is opposed to unpolarized light, which emits light in different directions and angles.
An example of polarized light is a laser, which has a well-defined electric field of light.
Polarized light can indicate to bees which direction food sources are located. When the sun is covered by clouds, the light it sheds through clouds creates a polarization pattern that bees can see.
The ocelli, otherwise known as simple eyes, detect polarized light and patterns. Bees find polarization patterns on flower petals, which is how they can detect them.
Who Is Karl Von Frisch?
Karl von Frisch is an Australian zoologist who made various discoveries about bees’ capabilities. The two main findings he published relate to the bees’ ability to see colour and communicate through dance.
Frisch used a colour card method to see which colours bees can detect. He would put a colour card among grey cards with a dish of sugar water on top of it for bees to feed. Then, he would remove the food source and see if the bees would visit the colour card, rather than the grey cards. The study proved that several colours are distinctive to bees.
His other discovery is that bees can communicate through dances in two forms: a round dance and waggle dance. These dances point other bees in the direction of polarized light, which leads to food sources.
Bees’ Eyes Detect Threats and Locate Food
All five of a bee’s eyes contribute in some way, shape, or form to their survival. Their eyes help them perceive a range of the visible light spectrum and polarized light, allowing them to detect threats and locate food sources.