Dolphins have fantastic eyesight. Even though they live underwater, the dolphins rely on their sight greatly. From finding their prey to avoiding attacks, their vision is their most important weapon for their survival. Dolphins’ eyes developed to see clearly both under and above the water’s surface. That is what makes the eyesight of a dolphin unique.
Can dolphins see in the dark?
Yes, the dolphins can see in the dark. Dolphins can see much better underwater than humans. The lens and cornea that the dolphins have in their eyes enable them to have accurate vision both inside the water and out. The unique thing is the dolphins also have rods and cones cells in their retinas. The rod and the cone cells are responsible for clear vision in bright and dim light. The dolphins have these cells in the retina to see in both situations.
A Dolphins Vision In The Dark
When it becomes dark under the water, the dolphins’ eyes can reflect dim light, just like a cat’s eyes.
The dolphins’ eyes contain tapetum, which helps to reflect the existing lights to the retina.
Even though the dolphins mostly use echolocation when they swim in the dark depths of water, they also have good eyesight thanks to the tapetum, which can sometimes be more successful in catching prey in the dark.
Another essential feature that the dolphins’ eyes have is that these marine animals can move their eyes independently of each other
whenever they want to. Much like when they sleep, they can close one eye and keep the other eye open.
Dolphins can virtually see in almost all directions. Their eyes are located on both sides of their heads. This feature also helps them to see in the dark effectively.
Unique Eye Ability Darkness To Day Light
Dolphins often break the water’s surface to breathe every eight minutes, so they need to adjust to both the high light intensity and the low light intensity.
Dolphins have strong muscles around their eyes that they can contract and expand whenever necessary. So, when the dolphins dive down to the darkest places, they loosen these muscles to make their eyes bigger so that more light can enter into their eyes, which, in turn, can help them to see easily from going to dark to light and vice versa.
The dolphins have developed large pupils to deal with this situation, which can bring in a large amount of light when they need it.
How do dolphins see humans?
The dolphins mostly use the sonar technique when they try to locate humans underwater. But when the dolphins break the water’s surface, they use their eyes to see the humans.
Eye Evolution Of A Dolphin (Land and Water)
As we already know, dolphins have evolved from land animals. So they still have all the eye-related features of the land animals that are important for them to see on land.
That is what makes the vision of the dolphins so unique compared to the other marine animals.
The eyes of the dolphins have evolved over millions of years in such a way that it does not lose focus when it goes underwater or come above the surface.
The dolphins have strong muscles around their eyes. They use these muscles effectively to change the shape of the lens of their eyes.
These unique physical characteristics of the dolphins enable them to see both in the air and underwater.
Marine animals need to have elliptical-shaped eyes to see underwater. But to see, the land mammals need spherical-shaped eyes.
The muscles located around the dolphins’ eyes help these animals change the lens from an elliptical shape to a spherical one and vice versa when necessary.
Can dolphins see above water?
Yes, the dolphins can see above water. The dolphins’ unique adaptation has helped these animals see both under and above the water’s surface. The fact is that dolphins have evolved from land mammals millions of years ago. While these marine animals have developed their eyes to adapt to the aquatic environment, they still possess the eyes of a land mammal. Whenever the dolphins break the water’s surface, they can see just like any other land mammals.
Even though these marine animals use sonar and echolocation techniques to navigate underwater, their eyesight is pretty good below and above the water’s surface.
The lens and the cornea that the dolphins’ eyes have helped dolphins to auto-correct the difference of light refraction present under and above the water’s surface naturally.
The dolphins also have strong muscles around their eyes, dilating and contracting, controlling the amount of light they want to enter into their eyes. Without this unique adaptation, the dolphins would be badly sighted when they reach the water’s surface.
Are dolphins colourblind?
Yes, dolphins are colourblind. They can only see different ranges of colours limited to the blue-green spectrum. Because they only have one cone cell located in the retina.
The cone cells are very sensitive to the light from various colour spectrums.
Take the human eyes, for example. We have three varieties of cone cells in our eyes. That is why we have a wide range of colour vision—most other marine or land animals that can see colour have at least two types of cone cells.
The problem is, the dolphins only possess one type of cone cells in their eyes. So this would indicate that they are colour blind and a possibility that the dolphins do not have any colour vision.