Welcome to our guide to hamster eye sight. Answering that all important questions ‘can hamsters see in the dark?’
If you own a hamster, you may get awakened at night when your little furry guy is running on his wheel. He’s definitely nocturnal, because he’s more active at night.
You have the sleep deprivation to prove it!
But what does that mean, in terms of your hamster’s senses? What is a hamster’s eyesight really like?
How does your hamster see the world? Let’s take a look.
How Your Hamster’s Eyes Work
Like all mammals, hamsters view the world through eyes made up of various parts.
When you look at something, light enters your eye. It first passes through the cornea, a transparent layer around the eye that allows both visible and ultraviolet light through.
Light then goes through the round opening called the pupil. The pupil regulates how much light enters the eye by shrinking in bright conditions and expanding in dark ones.
Then it passes through the lens, which filters some light and bends the light to allow focus.
After that, light goes through the gel-like vitreous body to become focused on the retina.
The retina is a surface at the back of the eyeball. It translates the light energy into electrical signals, which pass to the brain through the optic nerve.
The retina is made up of different cells, called rods and cones.
Rods and cones are photoreceptors. This means that they receive light, and then convert the light energy to signals that go to the brain. These signals then trigger biological processes, such as sleeping and waking patterns.
Rod cells are responsible for letting us see in low light conditions.
Cones let us see in bright light. We use them to see color and to make out shapes at different points in space. Cones have light-sensitive protein pigments, or photopigments, called opsins. These are sensitive to different wavelengths of light.
Most mammals have just blue and green opsins, and can therefore only see these two colors. Humans have red opsin as well.
Every animal has rods and cones, but may have them in different amounts. Animals that prefer to be active in the dark tend to have many rods, and not as many cones.
Hamsters fall into this category. Yes, they can see, but they see things differently than humans do.
The eyes of hamsters
In nocturnal animals, eyes are usually fairly large. The eyes have a big pupil and the surface of the retina is also large. This allows the eye to collect more ambient light.
Hamster eyes are mostly spherical. They come in a variety of colors ranging from bright and clear pink and dark red to brown and black. Color often depends on species.
Rodent eyes consist of the same parts as the human eye – including the iris, pupil, lens, retina, and the optic nerve.
There are some differences, however. For example, in humans the lens is flexible and can change shape. This does not happen in rodents. In hamsters, a proportionally larger lens allows in additional light.
Also, the pupil (the darker part in the center) is much more evident. The iris (the white part of a human eye) is smaller, and is not necessarily white.
That is why, unless you are looking closely at a hamster’s eye, it may just appear as a round, uniform color.
What do hamsters see?
Hamsters are born with a very poorly developed visual system. At birth they are blind and considered photophobic. This means they experience physical sensitivity (such as discomfort) in the eyes as a result of exposure to light.
Their overall sight is not very good, especially during the day.
Hamsters have mostly rod cells and a very small number of cones. Because cones provide color capability and general visual acuity, their eyesight is blurry. Rods give them good capability for seeing in low light conditions, however.
Studies have shown that hamsters do use their vision to investigate their food and catch insects. They also give each other visual social signals, as when they are being aggressive. They respond to high levels of light by ceasing activity.
So vision is important as an adaptation, because hamsters utilize visual cues in multiple ways.
Hamsters have a panoramic field of vision, and it is a binocular visual field. This means that, like humans, the fields of view from both eyes overlap. This gives them good perception of depth.
Can hamsters see in the dark?
But do hamsters see in the dark? And more specifically can Syrian hamsters see in the dark?
Well, not exactly.
They can’t see in complete darkness. As with humans, their eyes must receive some light to be able to make out objects.
In general, hamsters see best in dim light. They can make out objects with the most accuracy under low-light circumstances, as at dawn and dusk.
We don’t yet have any research to suggest that Syrian hamsters differ from other breeds in this respect.
Because of their poor eyesight, hamsters tend to use their other senses more often. Hearing, taste, and smell can all help hamsters make sense of the world around them.
Oversized teeth and whiskers are two adaptations allow hamsters to use their senses in the absence of good vision.
Do hamsters see in color?
So do hamsters see in color? And if so, what colors can hamsters see?
It is difficult to know exactly what colors animals can see. Not only is this dependent on the number of cones the animal has, it also has to do with how the brain processes the information.
Studies on Syrian hamsters have shown their eyesight is basically monochromatic. This means they see all colors as one color.
However, in studies hamsters did respond to blue and green stimuli. As a result, scientists now believe that hamsters may be able to see those colors, although perhaps only faintly. This is because of a light-sensitive pigment in the retina called rhodopsin.
Rhodopsin multiples in the rod cells during dark periods by combining Vitamin A with protein. This pigment absorbs most visible color, converting the light into energy. However, it is not equally reactive to all colors; it is mostly responsive to green.
Many nocturnal animals cannot perceive red, and may see just a small amount of blue.
Research does suggest that hamsters actually see through photopigments other than rhodopsin.
This means they may be able to see ultraviolet light!
Can Hamsters See UV?
Syrian hamsters react to ultraviolet radiation as if it is visible to them. Scientists believe that they may have additional photopigments that allow them to be sensitive to UV light.
But why would seeing in UV light be a good thing for hamsters? It’s hard to say. Hamsters would be able to see urine marks better under ultraviolet light…but so could predators.
It’s also possible that different animal parts reflect different amounts of UV light. If that is true, then certain body poses would make hamsters less visible to predators that can also see by UV light.
UV light is much more broadly available during the day and twilight hours. Thus, having UV vision could help hamsters navigate at those times, when they are awake.
So, to sum up, hamsters have fairly poor eyesight. They can’t see very well, but they make up for this lack with their other senses.
They see best in dim light conditions. This is an adaptation that probably allowed them to be most active at dawn and dusk.
Hamsters have decent depth perception, but their view of the world is mostly black and white with faded shades of green, and a bit of blue.
However, they do appear to see in the ultraviolet wavelengths. It is unclear whether this UV vision, and the limited color vision hamsters experience, has any real-world use today.
Take a look at your hamster’s eye. Can you see the various parts discussed in this article? Does he startle easily when something gets close?
Do you think your hamster can see green or blue items? Let us know! We’d love to hear about it in the comments section below.
Resources and Further Reading
- Brainard, G. C. et al (2001), “Influence of near-ultraviolet radiation on reproductive and immunological development in juvenile male Siberian hamsters,” The Journal of Experimental Biology, Vol. 224, 2535-2541.
- Calderone, J.B., and Jacobs, G.H.(1999), “Cone receptor variations and their functional consequences in two species of hamster,” Visual Neuroscience, 16(1), 53-63.
- Clive Roots, Nocturnal Animals (2006), Greenwood Publishing Group.
- Emerson, V. F. (1980), “Grating acuity of the golden hamster. The effects of stimulus orientation and luminance,” Experimental Brain Research, VOl. 38(1), 43-52.
- Finlay, B. & Berian, C. A. Barbara Finlay, “Visual and Somatosensory Processes” in Harold Siegel (ed.) (2012), The Hamster, Reproduction and Behavior, Springer Science & Business Media.
- Hanson, A. (2006), “What do rats see?” Rat Behavior, .
- Von Schantz, M., et al, (1997), “Photopigments and photoentrainment in the Syrian golden hamster,” Brain Research, Vol. 770, 131-138.
- “Exhibition Standards,” (2016), National Hamster Council.
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