Sharks have a limited color vision compared to humans. Their eyes are adapted to see contrast and movement in the water rather than a full spectrum of colors. While sharks can detect some colors, there is one color that sharks cannot see – the color red.
Quick Answer: Sharks Cannot See The Color Red
Sharks lack the photoreceptor cones in their eyes to allow them to see the color red. Their vision is based more on detecting contrast and movement. While sharks can see colors like green, blue, and yellow, they are unable to detect the color red.
How Shark Vision Works
Sharks have special eyes that allow them to see well in their ocean environment. Here are some key points about shark vision:
| Sharks have eyes on the sides of their head for a panoramic view |
| A reflective layer in the eye called the tapetum lucidum allows light to pass through the retina twice enhancing vision in dark or murky waters |
| Sharks can detect low levels of light due to a large number of rod cells in their retinas |
| They have few cone cells limiting their color vision |
The placement, structure, and composition of shark eyes allow them to detect contrast, movement, and low light situations effectively. However, the lack of cone cells results in limited color perception.
Sharks Lack Red Color Receptors
Humans have special photoreceptor cells in the retina called cones that allow us to see color. There are cones sensitive to red, green and blue light. The combination of signals from these cones allows us to detect the full visible color spectrum.
Sharks have an abundance of rod cells in their retina that detect light and dark contrasts. But they have very few cone cells. More importantly, sharks lack the red sensitive cone cells that would allow them to detect the color red. Without red cones, sharks are essentially color-blind to the color red.
Shark Color Vision Capabilities
While sharks cannot see reds, they do have some limited color vision:
| Can detect contrast, brightness, and fast movements |
| Sensitive to low light levels |
| Can see colors like green, blue and yellow |
| Likely see colors as shades of grey or black and white |
| Limited color vision helps camouflage from prey |
Sharks do have cone cells that respond to some colors in the blue to yellow wavelength ranges. However, their overall color perception is limited.
Without the red cones, sharks likely see most colors simply as shades of grey or in black and white contrast. The limited color vision sharks possess is sufficient for them to hunt and navigate through their underwater environment effectively.
Reasons Sharks Can’t See Red
There are a few key reasons why sharks are unable to see the color red:
| Lack red color receptive cones in their eyes |
| Red light wavelengths get absorbed and scattered in water |
| No evolutionary need to see reds for survival |
| Limited color vision helps hide from prey |
The simple lack of red cones in the shark retina prevents them from detecting reddish hues. But there are also some other factors that explain why sharks haven’t evolved the ability to see red colors.
Red light wavelengths tend to get filtered out and scattered as light passes through water. So there is less red light visible in the sharks’ aquatic environment.
Additionally, sharks evolved excellent vision acuity for detecting contrast and movement which is far more important for finding prey and avoiding danger than discerning color.
Their limited color vision even provides an evolutionary advantage as it helps camouflage sharks from potential prey.
Shark Vision Versus Human Vision
Shark vision and human vision differ quite significantly. Here is a comparison:
| Shark Vision | Human Vision |
| – Panoramic view | – Binocular vision |
| – Optimized for ocean | – Optimized for land |
| – Detects fast motion | – Better with stationary objects |
| – Low light sensitivity | – Limited night vision |
| – Mostly rods provide grey vision | – Cones provide color vision |
| – Can’t see red | – Can see full color spectrum |
As you can see, sharks have specially adapted vision to see action and contrast, especially in the low light ocean environment. Human eyes are better suited for seeing color, detail and stationary objects in bright settings. The lack of red cones and strong rod cell dominance sets shark vision distinctly apart from humans.
Do Blood And Lures Fool Sharks?
Myths suggest sharks go into a feeding frenzy in the presence of blood in the water. Movies also show bloody lures attracting sharks. But with the knowledge that sharks can’t see red colors, do blood and red lures actually work?
In truth, sharks are unlikely to be attracted by the red color of blood. However, they do have an exceptional sense of smell and can detect tiny concentrations of chemicals in the water using their olfactory system. Sharks can smell and follow the chemical cues from potential prey from a long distance away.
So while blood itself won’t be visually detected, sharks can smell and chemically analyze blood to identify prey. Injury also suggests vulnerability that can trigger shark feeding behavior.
Similarly, the success of red fishing lures is more likely due to the erratic movements which trigger shark aggression. The color red alone will not attract them.
Conclusion
In summary, sharks are unable to see the color red due to lacking the right photoreceptor cone cells in their eyes. While they do have some limited color vision in blues, yellows and greens, their vision is dominated by rod cells which provide excellent night and low light vision. But the lack of red cones makes sharks essentially colorblind to reddish hues. Their vision system evolution focused on detecting contrast, movement and low light situations rather than a full spectrum of colors. So when it comes to the question of what colors sharks cannot see, the answer is that sharks are blind to the color red.
